How To Dispose Used Smoke Detector Batteries

Have you wondered what you should do with an already used smoke detector battery? The truth is if you stick to regular maintenance policy, over a while, you’ll have a ton of used smoke detector batteries. So in this guide, we would find out what to do with already used smoke detector batteries, read through to find out.

What is a smoke detector?

A smoke detector is a device that combines smoke detection and a loud alarm together in one unit. The alarm sounds if it detects smoke in large amounts, like in a fire.

A smoke alarm, when properly installed, tested, and maintained gives you an early warning of a fire, which increases your chances of getting out.

How do I know which kind of smoke alarm I have?

A new alarm should be marked on the outside of the package to indicate if it uses ionization or photoelectric technology. Older units typically use the ionization detection method.

What’s the difference?

A photoelectric unit uses light to detect smoke.  It is preferred because it is better at detecting smoldering fires. These fires account for the greatest loss of life. Household fire warning systems, such as from ADT, only use photoelectric units.

Ionization smoke detectors use radiation to detect smoke.  These units are more effective in detecting flaming fires.  However, these units are more prone to nuisance false alarms caused by steam or cooking smoke. However, these units are ideal for placing in your garage.

How long will the battery last in my smoke alarm?

Actual battery service life depends on the particular design of your smoke or carbon monoxide alarm and the environment in which it is installed. All kinds of alarm batteries specified in the user’s manual are acceptable replacement batteries.

Regardless of the manufacturer’s suggested battery life, you MUST replace the batteries immediately once the unit starts “chirping” (the “low battery warning”). It is recommended that you replace the batteries in your alarms when you change your clocks for daylight saving time.

Also, consider replacing your current alarms with 10-Year Life Alarms that never require a costly battery replacement for the ten-year life of the alarm. This 10-Year series is available in smoke, carbon monoxide, and combination alarms.

When you’re ready to change my smoke alarm battery – what replacement batteries should you use?

Check your User’s Manual or the nameplate on the back of the alarm. Different smoke detectors use different kinds of batteries – 9V, AA, AAA – it all depends on the particular model you have. Use quality batteries like lithium smoke detector batteries – having plenty of power is worth any extra cost. Never use rechargeable batteries because they may not always provide a consistent charge.

How to Test Your Smoke Detector and How to Maintain It

Testing your smoke detector should become a part of your housekeeping routine and according to FEMA, should be done at least once a month.

While the specific way to test your detector depends on the manufacturer of your smoke detector, most detectors have an easily accessible test button on the face of the device. Once you press this button, wait a few seconds, and then a loud and piercing sound should emit from the device.

If you do not hear the device or if the sound is not loud enough, consider replacing the battery and test the device again. If the alarm doesn’t sound off even after you’ve replaced the battery, the device itself is probably faulty. Replace the detector as soon as possible.

Additionally, here are some guidelines you should follow while testing your smoke detectors:

  • Remember to test your smoke detectors monthly as suggested by FEMA. In many cases, this is as simple as just pushing a button.
  • Besides testing the device, clean out your smoke detector as well. Dust, spider webs, and other debris may hinder your smoke detector from operating at its maximum capability.
  • You should also replace the batteries at least once a year. Some systems, however, come with a “long-life” battery. These are usually not replaceable, and you may have to replace the smoke detector when the “long-life” battery runs out.
  • Figure out if your smoke detector is a stand-alone or is an interconnected model. A stand-alone model will only trigger itself when it detects smoke, while an interconnected model triggers all the alarms in the system if even one smoke detector goes off.
  • If you live in a large house, consider getting an interconnected system so that your whole residence is made aware of a house fire that may be happening on the opposite side of the house.
  • Station someone at the farthest areas of your house from your smoke alarm. When you test your alarm, they should be able to hear alarms go off. If they don’t, consider using an interconnected smoke detection system or get an alarm with a louder alarm.
  • Some smoke detection systems sold nowadays are also wired to inform your local fire station or home security system when it detects smoke. When testing your smoke alarm systems, notify your fire station so that they don’t send personnel to a non-existent fire.
  • They’ll be thankful for the heads up, and be glad that you’re diligently testing your smoke detection system.
  • Keep an up-to-date escape plan. These smoke detectors only alert you and cannot put out fires for you.
  • Check the dates on the back of your smoke detectors. Once an alarm reaches its 10-year life span, it is advised to replace it entirely. However, you can also consult the alarm’s manual as it may suggest replacing the entire system earlier.

How To Dispose of Smoke Detector Batteries

The most common type of smoke detector is an ionization detector which contains a small amount of Americium 241, a synthetic isotope that emits both alpha and gamma rays. The ingredient is shielded by a metal chamber within the plastic casing of the detector. This material poses little threat to human health or the environment. CT DEEP encourages finding alternatives to throwing smoke detectors in the trash.

Here are some tips that will help with the task and keep you and your family safe:

  • Pry before you buy

Most smoke alarms use 9-volt alkaline batteries, but some use AA. So if this is the first time you’ve replaced yours, do open the battery compartments on your units and check before heading to the store. You wouldn’t want to waste that extra hour.

  • Save the rechargeables for the remote

Green points for thinking of it, but alarm manufacturers do not recommend using rechargeable batteries because they tend to lose their charge faster. Rechargeable Batteries (including Li-Ion, Ni-Cd, Ni-MH, Ni-ZN, and SSLA/Pb): Do NOT put in the trash. Take to a retail collection location or a municipal recycling center that accepts rechargeable batteries. There are more than 400 collection sites in Massachusetts that are free to residents.

  • Skip the lithium batteries

Here’s another idea that sounds good in theory, but isn’t. While 9-volt lithium batteries last longer than alkaline batteries when they die, they die fast, says Consumer Reports. That means you’ll have less warning that they’ve gotten weak (your alarms should chirp if the batteries get low).

  • Go with a brand name

Why take the risk of using an off-brand just to save a few bucks?

  • There’s one way around this annual chore

There is an exception to the every-year rule. Some newer smoke alarms have a sealed lithium power supply that lasts the life of the alarm, 10 years. If your alarms have no visible battery compartment, this must be what you have. These alarms are about twice as expensive but will probably pay for themselves in batteries.

  • Is it time to replace the alarm itself?

The date it was manufactured should be on the back. Heat and smoke sensors get less sensitive as they age, so if it’s 10 years old, replace it.

  • Dispose of old batteries properly

Batteries often contain toxic metals, sometimes mercury. Some states don’t allow any type of battery to be thrown in the trash, so check your city or state’s rules.

Plus, used batteries often aren’t 100 percent dead yet. They can potentially be shorted by contact with each other or other metal objects, and then leak, overheat, or rupture. The super-safe thing to do, especially with 9-volt batteries, is to cover the contacts with masking, duct, or electrical tape.

  • Test your alarms monthly

Most people don’t, even though it’s incredibly easy: just push the test button. After all, things happen. You could get a dud battery, or it could get drawn down fast for some weird electrical reason. We recommend putting a monthly reminder on your home maintenance calendar. When you test, vacuum off dust too, to help prevent false alarms.

When disposing of Battery please understand the rule of Battery Disposal

Alkaline Batteries: Batteries currently manufactured in the United States contain no mercury and can be put in the trash.


Removing the battery from a smoke detector won’t set the unit off and start the fire alarm beeping. Instead, it will likely do the opposite and disable the unit. Because of this, there is really only one reason for you to ever remove the battery and that is to replace it with a fresh one. Also, used batteries can be disposed of properly in the garbage can.