Most AED batteries need replacing every two to five years, and the exact date is printed on the battery itself. Check that date, buy an FDA-approved replacement for your specific model, follow the manufacturer’s manual to swap it, and confirm the status indicator shows the device is ready. This guide walks you through each step, so a defibrillator in your school, childcare center, office or home is ready on the day someone needs it.

TL;DR

• Most AED batteries last about two to five years, depending on the manufacturer and model.
• Look for the “install by” or expiration date on a sticker on the back of the battery, often next to an hourglass symbol.
• Always follow your model’s operator’s manual, and buy replacements from authorized sellers with an FDA-approved label.
• After the swap, confirm the status indicator shows ready, then log the date and set a reminder for the next replacement.
• Do not put used lithium batteries in the trash. Take them to a battery recycler, a take-back retailer or a household hazardous waste program.

Table of Contents

• How long AED batteries last
• How to find your AED battery’s expiration date
• Replacing the battery step by step
• What to check after the swap
• Buying the right replacement battery
• Storing and disposing of the old battery
• Build a battery routine that does not depend on memory
• Our perspective: a ready AED is a trained team and a charged battery
• Get your team ready to use the AED
• FAQ
• Sources

How long AED batteries last

There is no single answer, because every manufacturer designs its battery differently. ZOLL’s maintenance checklist says batteries and pads can last anywhere from two to five years depending on manufacturer and model. The AF Association’s AED FAQs give the same two-to-five-year range.

Here is how that looks for a few common devices, straight from the manufacturers’ own documents:

Notice the detail in the Philips line. The battery has a shelf life before you insert it and a standby life after you do. The clock that matters most is the install-by date, so a spare battery sitting in a closet is not a way to avoid the schedule.

The ZOLL AED Plus entry shows another point: the right interval can depend on the software version inside the device. If you are not sure which applies to you, the manual and the manufacturer’s customer service line settle it.

What shortens battery life

The printed range assumes normal standby conditions and a device that is checked. Using the AED on a real rescue, running manual tests, or storing it outside the temperature range in the manual can all drain a battery faster. The AF Association advises that you always check the battery after any use to see whether it has been drained and needs replacing. Treat every activation, even a short one, as a reason to inspect the battery and pads.

How to find your AED battery’s expiration date

You do not need tools to find it. The King County (Washington) AED Maintenance Guide says the battery carries an “install by” or “expiration date” on a sticker on its back, often with an hourglass symbol. It also recommends recording the date the battery is installed, and puts the useful life at around four to five years depending on manufacturer.

Some models print the date where you can read it without removing anything. Others show it on the battery label only. Check your manual for the exact spot.

Read the status indicator too

The date is only half the picture. Your AED also tells you when something is wrong:

• On the Defibtech DDU-100, the unit indicates “battery low” or “replace battery now,” and the Active Status Indicator flashes red.
• Many devices chirp, show a red mark or display a warning when the battery is weak. Your manual lists the exact signals for your model.
• If the indicator shows nothing at all, the King County guide says to look for a cause, including a dead battery.

A chirp is not something to silence and ignore. Replace the battery, or call the manufacturer if you cannot tell what the alert means.

Replacing the battery step by step

The procedure differs by model, so the operator’s manual for your AED is always the final word. You can find it on the manufacturer’s website or through an authorized distributor. What follows is the general pattern, with details drawn from two manuals.

1. Gather what you need. Have the new battery, the operator’s manual and your maintenance log ready. Make sure the AED is not in use and the area is clear.
2. Check the new battery’s date. The ZOLL AED 3 manual says to confirm the new pack has not passed its install-by date before you replace anything. It also says to verify the defibrillator is turned off.
3. Remove the old battery. On the AED 3 you squeeze the side tabs to pull the old pack out. Other models use a latch or a release button.
4. Inspect the compartment. The Defibtech manual says to make certain the battery opening is clean before inserting the pack.
5. Insert the new battery. On the AED 3, hold the pack by the side tabs, line up the notch and push it in until it clicks. On the Defibtech DDU-100, orient the pack with the label facing up and insert it until the latch clicks.
6. Let the self-test run. Many AEDs run an automatic battery insertion self-test. The Defibtech unit does this on its own. On the Philips OnSite, the instructions say to remove the battery for five seconds and reinstall it to start the test.
7. Confirm readiness and record it. More on that below.

If you feel unsure at any point, the AF Association says to contact customer service for your model. That is a normal part of maintaining a device, not a sign you did something wrong.

Do you replace the pads at the same time?

Some AEDs use separate battery and pad components, and some use a combined cartridge. The two often have different expiration dates, so check both stickers. Replace whichever is expired or used, and keep a note of both dates in the same log.

What to check after the swap

A new battery in the compartment does not prove the AED is ready. Look for the manufacturer’s readiness signal:

• ZOLL AED 3: a green check and no beep after setup mean the battery pack and pads are installed properly and the AED is ready.
• Philips OnSite: after the self-test, check that the green Ready light is blinking.
• Defibtech DDU-100: a flashing green Active Status Indicator means the AED and battery pack are functioning properly.

If the device does not pass, do not shelve it and hope. The ZOLL AED 3 manual says to remove the battery, unplug the pads and repeat the steps, and if it fails a second time, to contact the manufacturer’s technical service department. Take the AED out of its public cabinet and post a notice that it is out of service until it is fixed, so no one reaches for a device that cannot work.

The same manual says to monitor status weekly and confirm the green check is showing. ZOLL’s maintenance checklist adds routine checks for physical damage, a visible and unobstructed storage location, and records of all maintenance.

Buying the right replacement battery

An AED battery is not a generic part. Use the exact model number from your manual or from the battery label. The ZOLL AED Plus guide, for example, says to use only Duracell Coppertop CR123 batteries made in the USA, so the wrong substitute can create a problem the self-test may not catch.

For price context, Philips lists its HeartStart OnSite, Home and FRx battery at $249.00. Prices vary by model, because some AEDs take a standalone pack and others a combined pad-and-battery cartridge, so confirm current pricing with an authorized seller.

Confirm it is FDA-approved

The FDA requires manufacturers to obtain premarket approval for all AEDs and AED accessories, and it encourages users to make sure their AED and accessories are FDA-approved. The agency also suggests that you:

• Buy accessories directly from authorized retailers.
• Find the unique device identifier (UDI) on the product label before you buy.
• Search that UDI in the AccessGUDID database.

The FDA also notes that compatible accessories for non-FDA-approved AEDs may no longer be available after February 3, 2022. If your AED is an older model, check with the manufacturer on whether batteries are still supplied for it.

Storing and disposing of the old battery

A “dead” AED battery can still hold energy. The US EPA says batteries can injure people or start fires even when used and apparently discharged. The EPA’s guidance for lithium single-use batteries is:

• Do not put them in the trash or municipal recycling bins.
• Take them to specialized battery recyclers, participating retailers with take-back programs, or local household hazardous waste collection.
• Tape the exposed terminals to reduce the risk of sparking.
• Store damaged lithium batteries in non-flammable materials until you can drop them off.

ZOLL states that both rechargeable and non-rechargeable AED batteries are classified as hazardous material, and that the EPA treats them as Universal Waste to be disposed of accordingly. The Defibtech manual likewise says battery packs should be recycled appropriately. Ask your manufacturer whether it offers a return program for your model.

Build a battery routine that does not depend on memory

The most common AED failure in a school or building is not a faulty device. It is a battery that quietly passed its date because no one owned the task. A few habits fix that:

• Name one person and one backup. Put both names on the maintenance log.
• Record the install date and the expiration date on the log and on a label next to the cabinet.
• Set a calendar reminder well ahead of the date, so there is time to order the right model.
• Check the indicator on a fixed schedule. Weekly matches the ZOLL AED 3 manual’s advice.
• Inspect after every use, even a short one.

Where the AED hangs matters as much as its battery. Our guide to AED placement guidelines covers where to put defibrillators so they are reachable and checked. If you run a campus, building an AED program for schools puts battery tracking alongside staff training and response planning. Staff who may need to use the device can read our practical guide to AED use in schools.

Our perspective: a ready AED is a trained team and a charged battery

We work every day with families, schools and caregivers who want to be ready when a child is in trouble. Over more than 20 years, one lesson has held steady: preparation is a habit, not a purchase.

An AED on the wall is reassuring. But a defibrillator is only as helpful as the last time someone looked at its indicator, and a battery is only as good as the date no one forgot. We encourage every team we train to treat the battery check like a fire drill: scheduled, logged and owned by a named person.

The second half of readiness is people. A responder who has practiced the steps is calmer, faster and more confident when the device says to attach the pads. That is why we pair device awareness with hands-on CPR and AED workshops, and with crisis management and prevention skills for school staff and caregivers who support children with autism, where a calm, rehearsed response matters just as much.

If your battery date is coming up, put the replacement on the calendar this week. Then make sure the people who would use the AED know where it is and how it works.

Jennifer

Get your team ready to use the AED

A fresh battery solves the device side. Building Block Resolutions also offers CPR/AED workshops and crisis management training for schools, organizations and caregivers, so the people around the AED know what to do. We can help you plan training for your staff or your family.

See what we offer on the Building Block Resolutions website, or browse our full list of services. If your CPR card is due, our guide to CPR certification renewal explains how blended training can be done in one to two hours.

FAQ

How long do AED batteries last?

Most last two to five years, depending on manufacturer and model. Examples include about four years typical standby for a Philips HeartStart battery installed by its install-by date and up to five years for ZOLL AED Plus batteries. Your battery’s label and manual give the exact figure.

Where is the expiration date on an AED battery?

Look for a sticker on the back of the battery marked “install by” or “expiration date,” often with an hourglass symbol. Some devices also show the date on the unit. Your operator’s manual shows the exact location for your model.

Can I replace an AED battery myself?

Yes. Manufacturers design the swap to be done by the owner. Follow your model’s operator’s manual, confirm the new battery has not passed its install-by date and wait for the self-test. If the AED fails the test twice, contact the manufacturer’s technical service.

What happens if my AED battery expires?

An expired battery may not deliver the power or pass the self-test the device needs, so you should not rely on it. Replace it before the date, and do not install a battery after its stated expiration date, as the Defibtech manual instructs. Take the AED out of service until the new battery passes its readiness check.

Sources

• How to Maintain an AED: Checklist and Tips, ZOLL Medical
• AED FAQs, AF Association US
• ZOLL AED Plus operator’s guide
• Philips HeartStart OnSite/Home/FRx battery
• Defibtech DDU-100 operator manual
• Stryker LIFEPAK 20e operating instructions
• King County AED Maintenance Guide
• ZOLL AED 3 Operator’s Manual
• Philips OnSite Defibrillator Instructions for Use
• Automated External Defibrillators (AEDs), FDA
• Used Household Batteries, US EPA

Recommended

• AED Placement Guidelines: Where to Put Defibrillators
• AED Use in Schools: A Practical Guide for Staff and Parents
• AED Program for Schools: How to Build One That Works
• Parents & Caregivers: AEDs for Children 1–8 — Pad Placement and When to Act