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Buying an AED is not like buying a fire extinguisher: nearly every unit sold today will technically shock a heart, but the details that decide whether it’s the right unit for your facility — waveform, pediatric readiness, the real multi-year cost of pads and batteries, and what your state actually requires once it’s installed — are easy to skip past on a spec sheet. This guide is written for people who are close to a purchase decision: a clinic or hospital facilities/safety manager standardizing AEDs across sites, a small-business owner or EMS coordinator buying one or two units, or an individual buying for a home, boat, or family business. It assumes you already know you need an AED; it’s here to help you pick the right one and stay compliant once it’s on the wall.
Biphasic vs. Monophasic: Why This Isn’t Really a Live Choice Anymore
Early AEDs and manual defibrillators used a monophasic waveform — current flows in one direction, and delivering an effective shock typically requires a higher energy dose (historically around 200–360 joules). Essentially every AED manufactured for sale today uses a biphasic waveform instead — current reverses direction partway through the shock, which resuscitation research found defibrillates effectively at meaningfully lower energy (commonly in the 120–200 joule range depending on the device) with less post-shock myocardial injury. Biphasic technology is now the de facto standard reflected in ANSI/AAMI DF80, the U.S. defibrillator device standard, and in current American Heart Association (AHA) resuscitation science.
In practice this means: if you’re buying new, every mainstream AED on the market is biphasic, so this isn’t a line item you need to compare between models — it’s a floor, not a differentiator. Where it does matter is if you’re evaluating a used or long-stored unit (see the cost section below) or an older donated device; a monophasic AED still in service is a strong signal the whole unit, including its pad/battery ecosystem, may be discontinued or hard to resupply.
Pediatric Readiness: Pads, Attenuators, and Dosing
Adult AED pads deliver a full adult energy dose, which is more current than current resuscitation guidance recommends for a small child’s heart. Current AHA guidance calls for a dose-attenuated pediatric pad set (sometimes built into a “pediatric key” or a dedicated pediatric cable) for children under roughly 8 years old or under about 25 kg (55 lb) — the attenuator reduces delivered energy to a pediatric-appropriate level using the same device. If pediatric pads aren’t available in a true emergency, AHA/ILCOR guidance is clear that using adult pads on a child in cardiac arrest is still preferable to not defibrillating at all — but that’s a fallback, not a purchasing plan.
What this means for selection: if your facility has any realistic pediatric exposure — a pediatric clinic, a school, a family practice, a daycare on-site, a public-facing retail or hospitality location, a home with children — confirm the model you’re buying has a pediatric pad/attenuator option sold by the same manufacturer, check its shelf life separately from the adult pads (pediatric pad sets are typically lower-volume SKUs and can lapse unnoticed), and budget for both pad sets in your replacement cycle, not just the adult set.
| Consideration | Adult-only deployment | Facility with pediatric exposure |
|---|---|---|
| Pad sets to stock | Adult only | Adult + pediatric attenuated set |
| Expiration tracking | Single date to monitor | Two independent expiration dates |
| Staff training | Standard AED use | Standard use + pediatric pad-swap procedure |
The Real Cost of Ownership: Pads and Batteries Over Time
The unit price on an AED is the smallest number in its lifetime cost. Two consumables drive the real total cost of ownership, and both expire on a shelf-life clock whether or not the device is ever used:
- Electrode pads ship pre-gelled and dry out over time even sealed and unused; manufacturers typically date them for somewhere in the 2–5 year range from manufacture, and a replacement pad set commonly costs somewhere in the low-to-mid hundreds of dollars depending on brand and whether it’s an adult or pediatric set — treat these as illustrative, model-dependent figures and confirm the exact date and price against your specific model’s manufacturer datasheet, not the device’s marketing page.
- Batteries are typically rated in a similar multi-year range, often 2–5 years depending on chemistry (lithium manganese dioxide primary cells are common and generally hold a longer shelf rating than some rechargeable alternatives) and how often the device’s self-test cycles draw on it; replacement cost again varies meaningfully by brand and is worth pricing before you commit to a model, not after.
Two practical selection questions follow directly from this: first, does the device run a daily/weekly self-test with a visible pass/fail indicator, so a dead battery or expired pad is caught by the device itself rather than at the moment of an emergency? Second, are replacement pads and batteries sold in the model you’re buying today going to still be sold in five years — a device from a manufacturer that has discontinued its consumables line is a device you may not be able to legally keep in service. Ask the vendor directly, and prefer a current-generation model from a manufacturer with an active consumables catalog over a discounted older model.
Regulatory Baseline: FDA, OSHA, and State Law
Three separate layers of regulation touch an AED purchase, and they don’t all say the same thing:
- FDA regulates AEDs as Class III medical devices. Since a 2019 final order, most AEDs sold in the U.S. no longer require a physician’s prescription to purchase — a meaningful change from the device’s original prescription-only status, intended to expand public-access placement. This does not remove the device from FDA oversight; it changes who can buy one, not how it’s regulated.
- OSHA has no standalone federal standard that mandates AEDs in a general workplace. Workplace first-aid obligations fall under the general first-aid provision, 29 CFR 1910.151 (“adequate first aid supplies” must be available, without specifying an AED by name), and the broader General Duty Clause (Section 5(a)(1) of the OSH Act). OSHA has published voluntary guidance encouraging AED programs, particularly where emergency medical response time is long, but “OSHA doesn’t require it” is not the same as “no one requires it” — see the next point.
- State and local law varies substantially and is frequently the layer that actually mandates something. A number of states require AEDs in specific building/occupancy categories (health clubs and fitness facilities, schools, certain high-occupancy or high-rise buildings, dental offices, and others are common categories), and separately, many states have Public Access Defibrillation (PAD) statutes that address AED ownership more broadly — commonly touching on registering the unit’s location with local EMS/9-1-1 dispatch so responders know it’s there, maintenance and inspection expectations, and Good Samaritan liability protection for anyone who uses it in good faith. Every U.S. state has some form of Good Samaritan protection that extends to AED use, but the exact scope, whether registration is required (and with whom), and whether a maintenance plan is mandated all vary by state. Because this is genuinely state-specific, confirm your state’s current requirements directly with your state health department or EMS office before finalizing a purchase and installation plan — don’t rely on a generic national assumption either way.
A Practical Selection Checklist
- Voice and visual prompts — clear step-by-step guidance for a non-clinical rescuer, since most real-world AED use is by a bystander, not a clinician.
- CPR feedback — a metronome or real-time compression-depth/rate feedback measurably improves bystander CPR quality; increasingly standard on current-generation units.
- Self-test cadence and indicator — daily or weekly automatic self-test with a visible ready/not-ready status, ideally visible from across a room.
- Environment rating — an indoor-cabinet unit has different durability needs than one mounted in a vehicle, loading dock, or outdoor-adjacent entrance; check the device’s IP (ingress protection) rating and operating temperature range against where it will actually live.
- Pediatric pad/attenuator availability — from the same manufacturer, in stock, not a discontinued accessory.
- Consumables availability — confirm pads and batteries are still in active production for the exact model, not a legacy line.
- Warranty length — AED warranties commonly run several years; get the exact term and what it covers (electronics vs. consumables, which are usually separate) in writing.
- Data/case review capability — relevant for clinical and multi-site buyers: some units log event data (rhythm, shock delivery, CPR metrics) for post-event quality review; a home or small-office buyer may not need this.
- Training alignment — confirm which certifying body’s course (AHA, American Red Cross, or equivalent) your staff will train on, and that the device matches what they’re trained on if you’re standardizing across a multi-site organization.
Buying for a Clinic or Hospital vs. a Home or Small Office
Multi-site clinical and institutional buyers generally get more value from standardizing on a single model across every location: it simplifies training (staff who float between sites see the same device), simplifies the consumables inventory a facilities or biomedical engineering team has to track, and makes post-event data review consistent. If your organization already runs a biomedical/clinical engineering maintenance program, an AED program should plug into the same preventive-maintenance and inspection cadence used for other patient-care devices — see our biomedical equipment maintenance guide for how that program is typically structured. Bulk and multi-unit buyers should also negotiate consumables pricing and replacement scheduling as part of the initial purchase, not as an afterthought once the first pad set expires.
Home, small-office, and individual buyers generally weigh cost and simplicity more heavily than fleet standardization, and the good news is the 2019 FDA rule change means most units are purchasable without a prescription. Prioritize clear voice prompts, a visible self-test indicator, and confirmed replacement-pad availability over advanced clinical features you’re unlikely to need. If you’re buying secondhand or a heavily discounted older model to save money, apply the same due-diligence discipline you would to any used lab or medical equipment purchase — our guide to buying used vs. refurbished equipment covers the general due-diligence checklist, and for an AED specifically, verifying the pad/battery expiration dates and confirming the exact model still has an active consumables line matters more than almost anything else on that checklist.
Sourcing Note
CASRAI and LAC (lac.us) are operated by the same group. If you’re ready to compare specific AED models and place an order, LAC’s AEDs & Defibrillators category is where our sister medical-supply catalog lists current units and accessories, including pad and battery replacement stock, for institutional and individual buyers.
Frequently Asked Questions
Do I need a prescription to buy an AED?
For most AEDs, no. A 2019 FDA final order removed the prescription requirement for most models sold in the U.S., allowing direct purchase by facilities and individuals. Confirm the specific model isn’t an exception before assuming this applies.
How often do AED pads and batteries need replacing?
It varies by manufacturer and model, but pads and batteries are both typically dated somewhere in a 2–5 year range from manufacture. Check the exact expiration printed on your specific pad set and battery, and confirm replacement cost and availability for your exact model before purchase, since this is where most of the device’s lifetime cost sits.
Note: AED consumable shelf-life and pricing figures above are illustrative, general ranges meant to help you budget and ask the right questions — always confirm exact dates and prices against the specific model’s current manufacturer datasheet.
Is an AED legally required at my facility?
There’s no general federal mandate. Whether one is required depends on your state and local law and your facility/occupancy type — several states require AEDs in specific settings such as health clubs, schools, or certain high-occupancy buildings. Check with your state health department or EMS office for your specific situation.
Can one AED serve both adult and pediatric emergencies?
Yes, with the right accessory: most adult AEDs can deliver a pediatric-appropriate dose using a manufacturer’s pediatric pad set or attenuator (typically recommended for children under about 8 years old or 25 kg). Confirm your model has this option and stock it alongside your adult pads if there’s any realistic chance of pediatric use.
Related reading: see our lab equipment hub for broader equipment planning and maintenance content, and our rapid response team activation criteria guide for how AED deployment fits into a broader institutional emergency-response program.
