Maintenance procedure · Written to ASD-STE100 Issue 9 · Formatted to ANSI Z535

Smoke Alarm Battery Replacement and Test

Household smoke alarms with a replaceable battery — battery change, monthly test, and the ten-year date check
ApplicabilityHousehold smoke alarms with a replaceable battery, within reach from the floor or from a stable step stool
Task time12 min to 16 min editorial estimate, not a measurement
PersonnelOne
Revisionv1 · 2026-07-29
BEFORE YOU BEGIN

Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.

Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.

Summary

A smoke detector that chirps once a minute is almost always asking for a battery, and the change itself takes about two minutes. The part people skip is the date. Every smoke alarm carries a date of manufacture on its back label, and the U.S. Fire Administration says the whole unit has to go ten years from that date. A new battery does not reset that clock. So this page does the date check first and the battery second, because there is no point buying a battery for an alarm that is already finished.

What this page will not do is tell you which battery to buy. The batteries a given alarm accepts are listed by the company that made it, and NFPA is explicit that you use those and not a substitute, so that value is published here as an instruction to go and read your own label. The page also stops where the reach stops: it covers an alarm you can touch from the floor or from a stable step stool, and nothing higher. Hardwired alarms are covered as far as the backup battery and no further, because the mounting plate and everything behind it is an electrician's work.

Safety

WARNING

DO NOT STAND ON A CHAIR OR ON A TABLE TO TOUCH THE ALARM.
You can fall and injure yourself. Use a stable step stool.

Necessary equipment

ItemNote
Stable step stoolThe step stool must have a wide base.
Flashlight optionalThe label on the back of the alarm is small.
Pen and paperUse these to record the date of manufacture.
New battery materialUse only a battery type that the manufacturer of the alarm specifies.

Prepare for the job

Estimated 2 min

NOTEThe alarm makes a very loud sound during the test. Tell the other persons in the home before you start.
  1. Put a step stool below the alarm.
    • The step stool must be stable.
    • The step stool must be on a level floor.
    • Make sure that the step stool does not move.
    1mReport a problem with step 1, Prepare for the job
  2. Tell the other persons in the home that the alarm will make a loud sound.
    <1mReport a problem with step 2, Prepare for the job

Read the date on the alarm

Estimated 3 min to 5 min

NOTEThe date of manufacture is not the date of purchase. The label on the back of the alarm is the only reliable source.
Alarm replacement age from the date of manufacture
Manufacturer or standard verified
10 years

Source: Smoke Alarms · tier 1 · accessed 2026-07-29

Date format on the back label
Unverified — do not rely on this value
READ THE DATE FROM THE LABEL ON THE BACK OF YOUR OWN ALARM

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

WARNING

DO NOT REMOVE THE MOUNTING PLATE OF AN ALARM THAT HAS WIRES.
The wires behind the plate can give you an electric shock.

  1. Turn the alarm counterclockwise to release it from the mounting plate.
    • Some alarms slide from the mounting plate.
    • Hold the alarm with one hand.
    • If the alarm has wires, do not disconnect the connector.
    <1mReport a problem with step 1, Read the date on the alarm
  2. Read the date of manufacture from the label on the back of the alarm.
    • The date format is different for each manufacturer.
    • A flashlight makes the small print legible.
    1mReport a problem with step 2, Read the date on the alarm
  3. Write the date of manufacture in your records.
    <1mReport a problem with step 3, Read the date on the alarm
WARNING

REPLACE AN ALARM THAT IS MORE THAN 10 YEARS OLD.
An old sensor can fail to sense smoke. A new battery does not correct this.

  1. If the date of manufacture is more than 10 years ago, replace the alarm.
    • Do not continue with this procedure.
    • A new battery does not increase the life of the alarm.
    <1mReport a problem with step 4, Read the date on the alarm

Replace the battery

Estimated 4 min

Battery replacement interval for a replaceable battery
Manufacturer or standard verified
1 year

Source: Smoke Alarms · tier 1 · accessed 2026-07-29

Permitted battery type
Unverified — do not rely on this value
CONSULT THE DOCUMENTATION FOR YOUR ALARM

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

  1. Open the battery compartment.
    • Some alarms have a battery door on the side.
    <1mReport a problem with step 1, Replace the battery
WARNING

INSTALL THE NEW BATTERY IMMEDIATELY.
An alarm without a battery cannot give a warning. This can kill the persons in the home.

  1. Remove the old battery.
    <1mReport a problem with step 2, Replace the battery
  2. Read the specified battery type from the label on the alarm.
    • The documentation for the alarm also gives the permitted battery types.
    <1mReport a problem with step 3, Replace the battery
WARNING

USE ONLY A BATTERY TYPE THAT THE MANUFACTURER SPECIFIES.
A different battery can make the alarm fail.

  1. Install a new battery of the specified type.
    <1mReport a problem with step 4, Replace the battery
  2. Make sure that the battery terminals agree with the polarity symbols.
    • The polarity symbols are the plus sign and the minus sign.
    <1mReport a problem with step 5, Replace the battery
  3. Close the battery compartment.
    <1mReport a problem with step 6, Replace the battery
  4. Install the alarm on the mounting plate.
    • Turn the alarm clockwise until it stops.
    • Make sure that the alarm is tight on the mounting plate.
    <1mReport a problem with step 7, Replace the battery

Do a test of the alarm

Estimated 2 min to 3 min

Alarm test interval
Manufacturer or standard verified
1 month

Source: Smoke Alarms · tier 1 · accessed 2026-07-29

CAUTION

MOVE YOUR HEAD AWAY FROM THE ALARM BEFORE YOU PUSH THE TEST BUTTON.
The alarm makes a very loud sound.

  1. Push the test button until the alarm makes a loud sound.
    <1mReport a problem with step 1, Do a test of the alarm
  2. Release the test button.
    <1mReport a problem with step 2, Do a test of the alarm
  3. If the alarm does not make a sound, replace the alarm.
    • An alarm that does not make a sound with a new battery is at the end of its life.
    <1mReport a problem with step 3, Do a test of the alarm
  4. Do the test again when a person listens in the most distant bedroom.
    • Close the doors between the alarm and the bedroom.
    • The person must hear the alarm through the closed door.
    2mReport a problem with step 4, Do a test of the alarm

After the job

Estimated 2 min

  1. Write the date of the battery replacement in your records.
    <1mReport a problem with step 1, After the job
  2. Make a monthly reminder for a test of the alarm.
    1mReport a problem with step 2, After the job
  3. Discard the old battery in agreement with the local rules.
    <1mReport a problem with step 3, After the job

Terminology

This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.

smoke alarm
Also called: smoke detector, fire alarm, fire detector, smoke sensor, ceiling smoke detector
date of manufacture
Also called: manufacture date, date code, born-on date, expiry date, expiration date
low battery signal
Also called: chirp, chirping, beeping, beep every 30 seconds, smoke detector keeps beeping
test button
Also called: test switch, check button
mounting plate
Also called: mounting bracket, base plate, trim ring, backplate

When to use a professional

Stop if you cannot touch the alarm when you stand on a stable step stool. Speak to your local fire department. Many fire departments do this work at no cost.

Stop if the alarm has wires. Do not remove the mounting plate. Do not disconnect the wires. A qualified electrician must do all work behind the mounting plate. NFPA gives the same instruction for the replacement of an alarm that has wires.

Stop if the alarm makes no sound after you install a new battery. Stop if the alarm continues to make a short sound after you install a new battery. This alarm is at the end of its life. Replace the alarm.

Common questions

Why does my smoke detector keep chirping after I changed the battery?

Because the chirp was probably never about the battery. NFPA's installation guide tells fire departments to replace on the spot any alarm that will not respond to a test after a fresh battery has gone in, and a chirp that survives a new battery is the same signal. Read the date of manufacture on the back label before you buy another battery. If it is ten or more years old, the alarm has reached the end of its life and no battery will fix it.

How often should I change the battery in a smoke detector?

At least once a year, according to both the U.S. Fire Administration and CPSC, and that includes the backup battery inside a hardwired alarm. NFPA adds the other trigger: change it the moment the low-battery indicator starts sounding, whenever in the year that happens. Alarms sold with a sealed ten-year battery are the exception, because there is nothing in them to change; you replace the whole alarm instead.

How do I know how old my smoke alarm is?

The date of manufacture is printed on the label on the back of the alarm, which means taking it off its mounting plate to read it. Kidde's support documentation says the same thing about its own alarms: the date code is stamped on the back label. The date you bought it or the date it was installed is not the number that counts, because an alarm can sit in a warehouse for a year before it is sold. The U.S. Fire Administration counts the ten years from the manufacture date.

What battery does my smoke alarm take?

This page deliberately does not say. NFPA's guidance is that you fit only the batteries the alarm's own manufacturer lists as replacements, and that list is model-specific. It is usually printed inside the battery compartment and always in the manual. Buying a battery that merely fits is the failure mode this rule exists to prevent.

Is a smoke alarm the same as a carbon monoxide detector?

No. They detect completely different things and a smoke alarm will not warn you about carbon monoxide. CPSC notes that combination smoke and CO alarms are sold, so one unit on your ceiling may be doing both jobs, but you cannot assume it. Check the label on the front of the unit.

Can I take the battery out when the alarm goes off while I am cooking?

No, and the U.S. Fire Administration puts it bluntly: disabling a smoke alarm or removing the battery can be a deadly mistake. Open a window or a door, press the hush button if the alarm has one, and wave a towel near the alarm to clear the air. If it keeps happening, USFA's advice is to move the alarm several feet further from the kitchen rather than to silence it.

Sources

Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.

  1. Tier 1Smoke AlarmsU.S. Fire Administration (Federal Emergency Management Agency) · accessed 2026-07-29 · re-verification due 2027-01-25
  2. Tier 1Planning & Implementing a Successful Smoke Alarm Installation ProgramNational Fire Protection Association · accessed 2026-07-29 · re-verification due 2027-01-25
  3. Tier 1CO AlarmsU.S. Consumer Product Safety Commission · accessed 2026-07-29 · re-verification due 2027-01-25
  4. Tier 1How to Find the Date of Manufacture on an AlarmKidde (Carrier Global Corporation) · accessed 2026-07-29 · re-verification due 2027-01-25
  5. Tier 1When Should I Replace My Alarms?Kidde (Carrier Global Corporation) · accessed 2026-07-29 · re-verification due 2027-01-25

Revision history

Current version 1 · updated 2026-07-29 · next review due 2027-07-29

  1. v1 · 2026-07-29First draft. Intervals from USFA, NFPA and CPSC; date-of-manufacture location from Kidde support documentation. Battery type and date format published as consult-the-manufacturer.

Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.

Comments and corrections

Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.

Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.

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