When to Replace AED Pads and Batteries
Automated External Defibrillators (AEDs) rely on two essential consumable components: pads and batteries. Both are critical for the device to function during a cardiac emergency.
Pads deliver the electrical shock to the patient, while the battery powers the AED to analyse heart rhythms and administer defibrillation if necessary.
It is vital to replace AED pads and batteries within the recommended timeframes. Expired or depleted components can cause the AED to malfunction, resulting in a failure to deliver treatment when required. Regular maintenance ensures the AED remains in a ‘rescue-ready’ state at all times.
Did You Know?
Defibrillator pads contain a conductive gel that can dry out after their expiry date, reducing the effectiveness of the shock.
Technical Lifespan Requirements
The replacement intervals for AED pads and batteries vary depending on the manufacturer and model. However, general guidelines apply across most devices.
AED Pads Lifespan
Defibrillator pads typically have a shelf life between 18 and 30 months. This is due to the conductive gel on the pads, which can degrade over time. Expired pads may not adhere properly or deliver shocks effectively. Manufacturers provide a clearly marked expiry date on each set of pads. After any use, pads must be replaced immediately, even if they have not reached their expiry date.
Examples:
ZOLL AED Plus: Pads expire after 5 years if unused (ZOLL UK).
Philips HeartStart HS1: Adult pads expire every 2 years (AED USA).
HeartSine Samaritan PAD: Pads come as part of a Pad-Pak with batteries, expiring after 4 years (Defib Supplies UK).
AED Battery Lifespan
Batteries usually last between 2 and 5 years, depending on model and usage. AED batteries must be replaced when they reach their expiry date or after use. Some devices include battery life indicators, or perform self-checks to alert users when the battery is low.
Examples:
Philips HeartStart HS1 battery: 4-year lifespan under normal standby conditions.
ZOLL AED Plus battery pack: Approximately 5-year shelf life with weekly self-tests (ZOLL UK).
HeartSine Pad-Pak: Battery and pads combined, replaced every 4 years (Defib Supplies UK).
Observation:
Expiry dates on AED pads are usually printed on the packaging but may fade if exposed to sunlight in outdoor cabinets.
Signs You Need to Replace Pads or Battery
While expiry dates are the primary guide, several other signs indicate when you must replace AED pads or batteries.
1. Expiry Dates Reached
Each set of pads and batteries comes with a manufacturer-stamped expiry date. Once expired, pads and batteries may not function correctly, even if they appear undamaged. Replacing them before this date ensures optimal AED performance.
2. After Any Use
Pads must always be replaced after use, regardless of their expiry date. Once applied to a patient, adhesive properties and gel conductivity degrade. Batteries should also be checked after a shock is delivered, as some AEDs use significant battery power during operation.
3. Device Self-Test Alerts
Most modern AEDs conduct daily, weekly, or monthly self-tests. If the device detects low battery power or expired pads, it activates a warning. These alerts can include:
Flashing or solid red indicator lights
Audible beeping signals
Displayed text or voice messages
Failing to respond to these alerts can result in a non-operational AED during emergencies (St John Ambulance).
Did You Know?
Some defibrillator models, like HeartSine Samaritan PADs, combine pads and batteries into one cartridge, making replacement simpler and reducing maintenance errors.
Maintenance and Inspection Best Practices
Regular inspection and maintenance are essential to ensure an AED remains operational. Following a set routine reduces the risk of equipment failure during an emergency.
Routine Inspection Intervals
Weekly Checks: Visually inspect the AED’s readiness indicator light and listen for audible alerts. Check pad expiry dates and battery indicators.
Monthly Checks: Perform a more detailed review, ensuring the pads are sealed, cables are untangled, and accessories such as scissors or razors are present.
Post-Use Checks: After any deployment, replace used pads immediately and review battery status.
Organisations like the British Heart Foundation (BHF) recommend registering AEDs on The Circuit, a national defibrillator network that sends reminders about upcoming maintenance needs (BHF Defibrillator Maintenance Guide).
Maintenance Records
Keeping a written or digital log of inspections, pad replacements, and battery changes supports compliance with workplace health and safety standards. Many public and workplace defibrillators have inspection tags attached to cabinets or cases for easy record-keeping.
Observation:
In many community settings, inspection logs attached to cabinets are left blank, potentially due to unclear local responsibilities.
Replacement Procedure
Replacing AED pads and batteries is a straightforward process, but it is important to follow manufacturer instructions carefully to maintain device readiness.
Step-by-Step: Replacing AED Pads
Check Expiry Date: Confirm that the replacement pads have a valid expiry date.
Turn Off AED: If required by the manufacturer, switch off the AED before changing components.
Remove Old Pads: Open the AED case, disconnect the old pads from the electrode port.
Install New Pads: Connect the new pads and place them securely in the designated compartment.
Check Readiness Indicator: Verify the device returns to ‘ready’ status, indicated by a green light or confirmation message.
Step-by-Step: Replacing AED Batteries
Obtain Correct Battery Model: Use the specific battery recommended by the manufacturer.
Turn Off AED (if applicable): Some AEDs require turning off the device before replacing the battery.
Remove Old Battery: Eject the battery by following the instructions (may involve releasing a latch).
Insert New Battery: Fit the battery securely until it clicks into place.
Conduct Self-Test: Most AEDs perform an automatic self-test after battery installation. Wait for a visual or audible signal confirming readiness.
Post-Replacement Check
After replacing either pads or battery, always:
Confirm the AED’s readiness light is green or active.
Record the replacement date and new expiry dates in the maintenance log.
Register the update on any monitoring systems such as The Circuit if applicable.
For detailed video guidance, many manufacturers offer free tutorials on their official websites (Defib Supplies Guide).
Disposal and Recycling
Proper disposal of used or expired AED components is essential for safety and environmental compliance.
Disposal of AED Pads
After Use: Treat used pads as clinical waste due to potential biohazard contamination. Follow local clinical waste disposal procedures.
Expired but Unused Pads: These can usually be disposed of in general waste, unless local regulations specify otherwise. Always check with your organisation’s waste management provider.
Disposal of AED Batteries
Battery Recycling: AED batteries, like other lithium or lithium manganese dioxide batteries, must not be disposed of in general waste. Instead, they should be recycled at:
Local authority recycling centres
Designated battery recycling points, often found in supermarkets or pharmacies
Disposal via Suppliers: Some AED suppliers, such as St John Ambulance, offer return and recycling schemes (SJA Maintenance Guide).
Legal Requirements
In the UK, the Waste Electrical and Electronic Equipment (WEEE) Regulations apply to AED batteries, requiring proper disposal and recycling to reduce environmental impact.
Did You Know?
Improper disposal of lithium batteries can cause fires in waste collection vehicles or recycling facilities, making correct recycling procedures critical.
Cost and Budgeting Estimates
The costs of AED pads and batteries vary depending on the device model and manufacturer. Planning for regular replacement ensures ongoing device readiness without unexpected expenses.
Typical Costs in the UK
AED Pads: Prices range from £30 to £150 per set. Adult pads usually cost less than paediatric pads. Combination Pad-Paks (pads and battery in one unit) can cost £90 to £160 (Defib Supplies UK).
AED Batteries: Replacement batteries cost between £80 and £250, depending on the model and battery lifespan.
Example Price Ranges:
AED ModelAdult PadsBatteryPhilips HS1~£45~£125ZOLL AED Plus~£100~£200HeartSine Samaritan PAD-Pak~£135 (pads & battery)—
Budgeting Considerations
Scheduled Replacement: Most organisations replace pads every 2–4 years and batteries every 3–5 years, making costs predictable.
Usage Replacements: Additional costs may arise if the AED is used in an emergency.
Bulk Purchase Discounts: Buying multiple replacement sets or service contracts can reduce unit prices.
Practical Tip
Organisations often budget £50–£100 per year for AED maintenance, depending on usage patterns and expiry timelines.
Observation:
Publicly accessible defibrillators in outdoor cabinets tend to require more frequent pad replacements due to temperature fluctuations affecting adhesive quality.
FAQs
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You should replace AED pads before their expiry date, usually every 18 to 30 months, depending on the manufacturer. Always replace pads immediately after use, even if unopened (St John Ambulance).
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Most AED batteries last between 2 and 5 years under standby conditions. Exact duration varies by model. Always check the battery’s expiry date and replace it after any use that involves delivering a shock.
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Expired pads may not adhere properly to the patient or deliver an effective shock. This can reduce the success rate of defibrillation during cardiac arrest, and you could be liable under workplace health and safety regulations.
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Yes, you can replace pads and batteries without special training. Manufacturers provide clear instructions, and many offer video guides. Always follow the device’s manual.
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Yes, some suppliers and organisations offer AED maintenance contracts or reminders through services like The Circuit by the British Heart Foundation, which notify you when components are due for replacement (BHF Defibrillator Maintenance).
Sources
Guide to Defibrillator Maintenance and Upkeep – St John Ambulance
Provides detailed guidance on pad and battery shelf‑life (2–5 years), what to inspect during self‑tests, and proper disposal methods.
https://www.sja.org.uk/get-advice/i-need-to-know/guide-to-defibrillator-maintenance-and-upkeep/A Guide to AED Maintenance – ZOLL Medical
Explains that pads and batteries typically last 2–5 years, offers manufacturer‑specific advice on inspection routines and environmental storage.
https://www.zoll.com/en-GB/Other-Resources-and-Links/how-to-maintain-aedWhat about monitoring and maintenance? – St John (New Zealand)
Details daily self‑tests, alert indicators (flash/beep), and confirms pads and batteries need replacing every 3–4 years or after use.
https://www.stjohn.org.nz/first-aid/about-aeds/defibrillator-faqs/what-about-monitoring-and-maintenance/
Source Commentary
These sources were selected for their authority and relevance. St John Ambulance and the British Heart Foundation offer nationally recognised guidance. Zoll and Philips (via AED USA) provide manufacturer-specific details. Defib Supplies offers up-to-date UK pricing. All links were verified as live and accurate at the time of writing.
