Most AED failures at the moment of cardiac arrest aren’t device defects — they’re consumables that quietly expired while nobody was watching the calendar. Pads in particular are the most predictable failure mode and the most preventable. Every set ships with a printed expiration date, every device runs a daily self-test, and every brand publishes a precise replacement window. The only thing standing between a working AED and a paperweight is whether someone scheduled the replacement before the gel dried out.
This guide is the operational replacement schedule for every major AED brand sold in the United States — when pads expire, why they expire, and the calendar workflow that keeps a fleet of devices rescue-ready without scrambling at the last minute.
Why AED pads expire
The pad itself is more chemistry than electronics. Each adult pad contains:
- Conductive hydrogel — a water-based gel matrix that transmits electrical current from the device into the patient’s chest while spreading it evenly enough to avoid skin burns.
- Pressure-sensitive adhesive — a tackifier that holds the pad against the chest during CPR compressions without lifting.
- Foil-laminated sealed pouch — protects gel + adhesive from atmospheric moisture loss.
Over time, all three layers degrade. The hydrogel slowly loses water through the pouch seal; the adhesive’s tack diminishes; the foil pouch can develop micro-leaks. Once gel viscosity changes, the pad’s resistance changes — and at the moment of defibrillation, that can mean a failed shock or an uneven energy delivery that injures skin without restoring rhythm.
The 2026 brand-by-brand pad replacement schedule
| Brand & model | Pad shelf life | Replacement frequency | Replacement count over 10 years |
|---|---|---|---|
| Philips HeartStart OnSite / Home (M5071A) | 2 years | Every 24 months | 5 sets |
| Philips HeartStart FRx (SMART Pads II) | 2 years | Every 24 months | 5 sets |
| Philips FR3 (clinical) | 2 years | Every 24 months | 5 sets |
| ZOLL AED Plus (CPR-D Padz) | 5 years | Every 60 months | 2 sets |
| ZOLL AED 3 (CPR Uni-padz) | 5 years | Every 60 months | 2 sets |
| HeartSine 350P / 360P / 450P (PAD-PAK combined) | 4 years | Every 48 months (pads + battery together) | 2.5 sets |
| Defibtech Lifeline / VIEW (DDP-100) | 2 years | Every 24 months | 5 sets |
| Cardiac Science Powerheart G3 / G5 | 2 years | Every 24 months | 5 sets |
| Physio-Control LIFEPAK CR2 (Quik-Step) | 2 years | Every 24 months | 5 sets |
| Physio-Control LIFEPAK 1000 | 2 years | Every 24 months | 5 sets |
For complete pad cost comparisons across brands, see our AED Pad Replacement Cost by Brand guide.
The “pre-expiration window” framework
The expiration date printed on the pad pouch is the last day the pads are guaranteed safe — not the day to start ordering. Best practice is a tiered pre-expiration window for every deployed AED:
T-minus 90 days · Procurement window
Add replacement to the next month’s purchase order. Confirm budget allocation. Verify supplier inventory for the exact brand/model.
T-minus 60 days · Order placed
Order replacement pads from an authorized reseller. Confirm shipping lead time. For fleet orders, batch multiple AEDs into one PO for a bulk discount.
T-minus 30 days · Pads in hand
Replacement pads arrive on-site. Inspect packaging for damage. Verify expiration date stamped on new pouch (should be ~24 months from receipt for 2-year pads).
T-minus 7 days · Replacement installed
Designated maintainer installs new pads. Log replacement date in the maintenance log. Sets next reminder. Disposes of old pads via approved channel.
T-zero · Expiration date
By this date, replacement is complete. The daily self-test indicator should show green throughout. No gap in readiness.
Calendar workflow that actually works
Three common pad-replacement workflows in U.S. facilities:
Workflow A — Single AED, household or small business
At install, set a recurring digital calendar reminder for the expiration date minus 90 days. Use a shared calendar accessible to multiple household members or employees so the reminder doesn’t depend on one person.
Workflow B — Small fleet (2–10 AEDs)
Consolidate all AED expiration dates into a single spreadsheet. Sort by next-expiring. Run a quarterly review — every quarter, check which devices have replacements due in the next 6 months and bulk-order those together. Captures ~10% bulk discount and ensures no device falls through the cracks.
Workflow C — Large fleet (10+ AEDs)
Use AED fleet-management software (AEDTS, Atrus, AED Sentinel, similar). Every device is tagged with model, serial, location, install date, and consumable expiration dates. Software sends automated email reminders to the designated maintainer 90/60/30/7 days before expiration. For multi-site organizations, this is the difference between a controlled program and a chronic firefighting cycle. Learn more about AED fleet management at AEDTS.
The “ZOLL discount” on long-life pads
ZOLL CPR-D and CPR Uni-padz are unique among major brands at 5-year shelf life. Across a 10-year deployment lifecycle, ZOLL pads need 2 replacement cycles versus 5 cycles for Philips, Defibtech, Cardiac Science, or LIFEPAK. The downstream effect:
- Fewer purchase orders to process
- Fewer expiration dates to track per device
- Fewer install events where the AED is temporarily out of service
- Lower total administrative burden across the fleet
For organizations that prioritize maintenance simplicity over per-unit features, the operational economics of ZOLL or HeartSine PAD-PAK can meaningfully reduce program friction.
What happens to expired pads?
Used and expired AED pads are technically biohazard-adjacent (potential blood contact in deployment) and contain conductive gel. Best practice for disposal:
- Unused expired pads in sealed pouch: Standard solid waste in most jurisdictions; some manufacturers offer mail-back programs alongside battery returns.
- Used pads after a deployment: Treat as biohazard waste. Some facilities have an existing biohazard contractor; others coordinate with local EMS for disposal.
- Foil pouches: Recyclable as metalized film in some markets; many municipalities require landfill.
See our AED Battery Disposal article for the parallel battery-disposal workflow.
The hidden risk: counterfeit pads sold below MSRP
The FDA Safety Communications have flagged a rising volume of counterfeit AED pads marketed through online marketplaces at 30–60% below MSRP. Counterfeit pads can fail to conduct properly, separate from the chest during CPR, or cause skin burns. The two red flags:
- Pricing is dramatically below the manufacturer’s MSRP from unauthorized sellers
- Pouches without FDA Unique Device Identifier (UDI) markings
Always purchase replacement pads from manufacturer-authorized resellers — AED Leader and similar specialty retailers maintain authorized distribution.
Frequently Asked Questions
How often should AED pads be replaced?
Most AED pads expire every 2 years (Philips, Defibtech, Cardiac Science, LIFEPAK). ZOLL pads last 5 years. HeartSine PAD-PAK combines pads + battery into a 4-year cartridge. Replace on or before the manufacturer-printed expiration date.
Why do AED pads expire?
Conductive hydrogel in the pad slowly loses moisture, adhesive degrades, and the sealed pouch can develop micro-leaks. After expiration, pads can fail to deliver therapy or cause skin burns during defibrillation.
What if I miss the expiration date?
Replace expired pads immediately — within 7 days at the latest. An AED with expired pads is not considered rescue-ready, may void Good Samaritan immunity in some states, and may fail to deliver a shock at the moment of cardiac arrest.
When should I order replacement pads?
Order 60–90 days before expiration. This builds in shipping time, lets you batch orders for bulk discount, and ensures no gap in device readiness. Set a recurring calendar reminder at install.
Do AED pads have different shelf lives when stored differently?
Yes. Pads stored above 80°F or below 35°F lose stated shelf life by 10–20%. For unheated outdoor cabinets in cold climates, plan replacement at ~75% of stated life.
Can I check the pad expiration without opening the AED?
Yes. Modern AEDs run a daily self-test that includes pad-presence verification, and most surface the expiration date in their status indicator or display. The expiration date is also printed on the sealed pouch visible through the cabinet window on most cabinet designs.
Are pad replacement schedules different for pediatric pads?
Pediatric pad shelf life is typically the same as adult pads of the same model — 2 years for most brands, 4 years for HeartSine pediatric PAD-PAK. Stock both adult and pediatric pads with synchronized expiration calendars.
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Sources & References
- FDA — Automated External Defibrillators
- FDA — Medical Device Safety Communications
- American Heart Association — Public AED Resources
- Manufacturer documentation: Philips HeartStart, ZOLL AED, Defibtech, HeartSine, Cardiac Science, Physio-Control
- AEDTS — AED Fleet Management
Disclaimer: Pad shelf life is manufacturer-specific. Always verify against the expiration date printed on each pad pouch. AED pads require an FDA-issued physician prescription and should be purchased through authorized resellers only.
