An AED that still powers on is not the same as an AED that is still rescue-ready. Here is how to tell the difference before an emergency forces the question.
The 30-Second Answer
Most AED units have a manufacturer-designed service life of 8 to 10 years from the date of manufacture. Beyond that age window, watch for these signals that replacement is due sooner: repeated self-test failures even after replacing pads and battery, physical damage to the casing or connectors, the manufacturer no longer selling replacement pads or batteries for your model, an active recall the manufacturer cannot remedy, and any feature gap (no pediatric mode, no CPR feedback) that no longer matches what your location actually needs. The full list of 7 signs is below.
An AED that turns on and passes its self-test looks fine. That is exactly what makes AED replacement decisions harder than most equipment replacement decisions: the device gives no dramatic indication that it is approaching the end of its useful life. It simply keeps working, right up until the moment a component fails during an actual rescue or the manufacturer can no longer supply the pads it needs to function.
This article walks through the specific warning signs that indicate replacement, not just routine pad or battery replacement, is the right call, along with the brand-specific expiration data you need to plan ahead rather than react.
What This Article Covers
- 7 warning signs your AED needs replacing
- How long does an AED unit actually last?
- Pad and battery expiration, brand by brand
- Can you use expired pads in an emergency?
- How often should an AED be professionally inspected?
- Automating expiration alerts
- What to do once you decide to replace
- Frequently asked questions
1. 7 Warning Signs Your AED Needs Replacing
Routine pad and battery replacement is normal maintenance, not a warning sign. These 7 signs indicate the AED unit itself, not just its consumables, is the problem.
It is approaching or past 8 to 10 years old
Most AED manufacturers design units for an 8 to 10 year service life from date of manufacture. Age alone does not mean immediate failure, but it is the point to start actively planning replacement rather than waiting for a failure.
Repeated self-test failures after fresh pads and battery
If the AED still shows an error or fails its self-test after you have installed current, unexpired pads and a new battery, the problem is in the device itself, not the consumables. This is one of the clearest replace-now signals.
The manufacturer no longer sells replacement pads or batteries
Older or discontinued platforms sometimes lose consumable support entirely. An AED you cannot legally or practically resupply is not a functioning safety device, regardless of whether it still powers on.
Physical damage to the casing, buttons, or ports
Cracked housings, unresponsive buttons, corroded connector ports, or a display that no longer reads clearly are liabilities during the exact moment the device needs to work flawlessly and fast.
An active recall the manufacturer cannot remedy
Some recalls are resolved with a software update or a component swap. Others affect the underlying hardware in a way that cannot be corrected. Check your specific model against current FDA recall notices.
It no longer matches what your location actually needs
An AED without pediatric pad availability at a location that now serves children, or without CPR feedback at a site with mostly untrained responders, may be functionally obsolete for your program even though the unit itself still works.
Software support has ended for the platform
Some manufacturers stop issuing firmware and rhythm-analysis algorithm updates for older platforms well before the hardware's mechanical service life ends. A device that can no longer receive current protocol updates is falling behind clinical best practice.
One sign alone (especially age) is a planning cue, not an emergency. Two or more signs together, particularly repeated self-test failures or a discontinued consumable supply, mean replacement should move from "someday" to "this budget cycle."
2. How Long Does an AED Unit Actually Last?
Most current-generation AEDs are designed for an 8 to 10 year service life from date of manufacture, consistent across the major brands. Actual lifespan depends heavily on storage conditions and usage: a unit kept in a climate-controlled office cabinet and used rarely will typically outlast one mounted in a vehicle or an outdoor cabinet exposed to temperature extremes.
Warranty length gives a useful secondary signal: new AEDs typically carry manufacturer warranties up to 8 years, while refurbished units carry shorter reseller warranties, typically 1 to 4 years. Once a unit is well past its original warranty and showing any of the 7 signs above, replacement planning should begin.
3. Pad and Battery Expiration, Brand by Brand
Consumable expiration is separate from unit replacement, but tracking it closely is what prevents most AED failures. The table below shows typical expiration cycles by brand; always confirm against the specific date printed on your pads and battery, since exact figures vary by model within a brand.
| Brand | Typical Pad Expiration | Typical Battery Expiration |
|---|---|---|
| ZOLL AED Plus | Approximately 5 years | Approximately 5 years (lithium 123A cells) |
| ZOLL AED 3 | Varies by configuration, check printed date | Varies by configuration, check printed date |
| Philips HeartStart OnSite / Home | Approximately 2 years | Approximately 4 years |
| HeartSine samaritan PAD (Pad-Pak) | Combined cartridge, approximately 4 years for both | |
| Defibtech Lifeline | Approximately 2 years | Typically 4 to 7 years depending on model |
| Cardiac Science Powerheart (G3 / G5) | Approximately 2 years | Varies by model, check printed date |
| Physio-Control / Stryker LIFEPAK | Approximately 2 years | Approximately 3 years |
An unopened, unused set of pads still expires by its printed date. The conductive gel that lets the pads read heart rhythm and deliver a shock degrades over time regardless of whether the packaging has ever been opened. Storing spare pads does not pause the expiration clock.
4. Can You Use Expired Pads in an Emergency?
This is the single most important safety question in AED maintenance, and it deserves a direct, honest answer rather than a simple yes or no.
Expired pads may not adhere to the patient's skin as reliably, and the conductive gel may not transmit the shock as effectively, because the gel dries out over time. This means expired pads carry a real risk of reduced rescue effectiveness. They are not guaranteed to fail, but they are not guaranteed to work either, and an AED's entire value proposition depends on working when it matters most.
If expired pads are genuinely the only pads available during an actual cardiac arrest, using them is better than attempting no defibrillation at all, because any attempt carries a chance of success where no attempt guarantees none. However, this is a last-resort scenario, not an acceptable operating condition. The correct answer is to never be in that position: replace pads before their expiration date, every time, so this question never has to be answered in the moment it matters.
Do not keep expired pads on hand "just in case" as a substitute for current ones. Dispose of them properly and replace them promptly; see our AED Inspection Checklist for a routine that catches expiration before it becomes urgent.
5. How Often Should an AED Be Professionally Inspected?
Two different inspection cadences apply, and conflating them is a common source of confusion.
- Monthly self-inspection (owner or program manager). Check the visible status indicator, confirm the display shows no error, and visually inspect for physical damage. This takes under two minutes and is the single highest-value habit in any AED program.
- Formal professional inspection. Manufacturer guidance commonly recommends inspection at least biannually (twice yearly), though specific state legal requirements vary. A formal inspection typically includes verifying self-test history, confirming pad and battery expiration dates, checking cabinet and signage condition, and updating the maintenance log.
State-specific inspection requirements can be stricter than manufacturer guidance, particularly for schools and licensed facilities. See our AED Laws & Compliance hub for state-by-state detail.
6. Automating Expiration Alerts
For organizations managing more than a handful of AEDs, manual monthly inspection across every unit becomes a real administrative burden, and the most common point of failure. Automated options exist at two levels.
- Smart-chip pad monitoring. The Cardiac Science Powerheart G5 reads pad expiration directly from a smart chip embedded in the pad connector and alerts automatically as expiration approaches, removing reliance on manual date-checking for that specific brand.
- Wi-Fi and Bluetooth connected AEDs. Models like the ZOLL AED 3 and Physio-Control LIFEPAK CR2 can send automatic readiness alerts to a program manager's email or phone.
- Third-party program management software. Platforms like Stryker LIFELINKcentral, Cardiac Science AEDSafetrack, and ZOLL's LifeShield consolidate expiration tracking, compliance documentation, and sometimes medical oversight across an entire multi-unit fleet, typically for a subscription in the range of $50 to $200 per AED per year.
Single-unit deployments generally do not need paid software; a monthly calendar reminder tied to the printed expiration dates is sufficient. Multi-location programs benefit disproportionately from automation, since the administrative burden scales with unit count. See our full AED Total Cost of Ownership breakdown for how program management software factors into long-term budgeting.
7. What to Do Once You Decide to Replace
- Decide new versus refurbished. A refurbished replacement can reduce cost by 30 to 50 percent with no clinical performance trade-off when sourced from a verified refurbisher. See New vs Refurbished AED.
- Reassess brand and feature fit, not just a like-for-like swap. Replacement is the natural moment to add pediatric capability, CPR feedback, or a higher IP rating if your location's needs have changed since the original purchase. See AED Features That Actually Matter.
- Register the new unit and update your program documentation. Update your written AED program policy, local EMS registration, and responder training records to reflect the new device.
- Properly dispose of the old unit. Old AEDs and their battery packs are considered hazardous waste in most jurisdictions and should go to a hazardous waste or electronics recycling facility rather than the regular trash. Expired pads can typically go in regular trash or recycling.
- Confirm the new unit's consumable supply chain before you need it. Especially for less common brands, confirm genuine OEM pads and batteries are readily available before committing to a specific replacement model.
For a full brand comparison and current pricing, start with our Complete AED Buyer's Guide or call (855) 286-6384 to discuss trade-in and upgrade options for your specific model.
8. Frequently Asked Questions
How long does an AED machine last?
Most current-generation AED units have a manufacturer-designed service life of 8 to 10 years from date of manufacture, consistent across major brands. Actual lifespan depends on storage conditions and usage frequency; a unit stored in a climate-controlled indoor cabinet typically outlasts one exposed to vehicle storage or outdoor temperature extremes. This is separate from pad and battery expiration, which follow their own, much shorter replacement cycles throughout the unit's life.
Do AED pads expire if the package is unopened?
Yes. The conductive gel on AED pads degrades over time regardless of whether the packaging has ever been opened. Sealed, unused pads still expire by the date printed on the package, typically 2 to 5 years from manufacture depending on brand. Storing a spare unopened set does not pause the expiration clock, so spare pads need the same expiration tracking as the pads currently connected to the AED.
How often should an AED be professionally inspected?
Manufacturer guidance commonly recommends formal inspection at least biannually (twice yearly), in addition to monthly self-inspection by the AED's owner or program manager. Specific state legal requirements can be stricter, particularly for schools and licensed facilities; verify current requirements for your jurisdiction. See Section 5 for the distinction between routine self-checks and formal inspection.
When should you replace an AED battery?
Replace the battery by the expiration date printed on the battery itself, typically 2 to 5 years from manufacture depending on brand (ZOLL AED Plus batteries run approximately 5 years; Physio-Control LIFEPAK batteries approximately 3 years; Philips approximately 4 years). Also replace the battery immediately after any actual rescue deployment, since defibrillation and extended use draw significant power even if the original expiration date has not been reached. AEDs perform periodic self-tests that gradually deplete the battery over time, which is why batteries can reach end of life even without ever being used in a rescue.
What is the life expectancy of a Zoll AED?
The ZOLL AED Plus unit itself has the same 8 to 10 year design service life as other major brands. What makes ZOLL distinctive is its consumables: ZOLL AED Plus pads (CPR-D-padz) and its lithium 123A battery both carry an unusually long approximately 5-year replacement cycle, compared to the 2-year pad cycle common on most competing brands. This longer consumable cycle is one reason the ZOLL AED Plus is frequently recommended for low-maintenance small business and workplace programs; see our comparison in Best AEDs for Small Business.
Can you use expired AED pads in an emergency?
Expired pads carry real risk of reduced effectiveness because the conductive gel dries out over time, which can affect adhesion and shock delivery. If expired pads are genuinely the only option available during an actual cardiac arrest, using them is better than not attempting defibrillation at all, since any attempt carries a chance of success where no attempt guarantees none. However, this is a last-resort scenario, not an acceptable operating condition. The correct practice is to replace pads before they expire so this question never needs to be answered in the moment. See the full discussion in Section 4.
Can I automate expiration alerts so I don't have to check every unit manually?
Yes, through a few different mechanisms. The Cardiac Science Powerheart G5 uses a smart chip embedded in its pads that reports expiration status directly to the AED. Wi-Fi and Bluetooth connected models like the ZOLL AED 3 and Physio-Control LIFEPAK CR2 can send automatic alerts to a program manager. For multi-brand or multi-location fleets, third-party program management software (Stryker LIFELINKcentral, Cardiac Science AEDSafetrack, ZOLL LifeShield) consolidates tracking across every unit, typically for $50 to $200 per AED per year. Single-unit programs usually do not need paid software; a calendar reminder tied to the printed expiration dates is sufficient. See Section 6 for detail.
Total AEDs ships free on orders $149 and above within the contiguous United States. See our full shipping policy and return policy before ordering, or call (855) 286-6384 to discuss trade-in and replacement options for your specific AED model.
