A monthly AED check takes about two minutes and follows the same basic steps regardless of brand: verify the status indicator, inspect the pads and battery dates, check the cabinet, and confirm the rescue kit is stocked. Doing this consistently is what separates a life-saving device from an expensive wall decoration.
Nearly half of reported AED failures happen when the device tries to charge and deliver a shock during an actual emergency, according to a Sudden Cardiac Arrest Foundation analysis. Pad and connector problems account for about 24% of failures, and battery issues account for another 23%. A simple monthly visual inspection catches most of these problems long before someone’s life depends on the device.
Step 1: Check the Status Indicator
Every AED runs automatic self-tests (daily or weekly, depending on the model) and displays the result through a status indicator. Your first job each month is to look at that indicator and confirm the device is reporting “ready.” Depending on your AED model, a passing self-test shows up as a green light, a check mark, or an hourglass symbol.
If something needs attention, the AED will show a flashing red light, a red “X,” or emit a chirping sound. A chirp typically means maintenance is required. If the device shows no status indicator at all, check whether the unit is powered on and inspect it immediately for a dead battery. An AED with no status indicator should be removed from service until the problem is resolved.
Step 2: Inspect the Unit for Physical Damage
Look over the entire AED housing for cracks, dents, or any foreign substances on the device. Open the lid and visually confirm the electrode pads are still sealed in their packaging. Damaged housing can let moisture in and corrode internal components, and torn pad packaging dries out the conductive gel that makes the pads work.
Step 3: Verify Battery and Pad Dates
This is the step people most often skip, and it’s the one most likely to cause a failure. Write down two things: the date the battery was installed and the expiration date printed on the electrode pads (both adult and pediatric, if you stock both).
AED batteries last between two and five years in standby mode, but the range varies significantly by manufacturer. Cardiac Science and Philips HeartStart batteries last roughly four years. Physio-Control LIFEPAK batteries run closer to three years. ZOLL batteries last about five years. Defibtech batteries range from four to seven years depending on the model. Heartsine Samaritan batteries last approximately three and a half years. Regardless of brand, a battery should be used within five to seven years of its manufacture date, even if the device hasn’t flagged it yet.
Electrode pads have a shelf life of two to four years. Expired pads may not adhere properly to a patient’s chest or conduct the electrical impulse reliably. If either the battery or pads are within a few months of expiration, order replacements now rather than waiting.
Step 4: Check the AED Cabinet
If your AED is stored in a wall-mounted cabinet, verify four things:
- Visibility: The cabinet is clearly visible and not blocked by furniture, boxes, or signage.
- Access: The cabinet door opens and closes easily.
- Alarm: If the cabinet has a door alarm, open it and confirm the alarm sounds. This alert notifies staff when someone pulls the AED for an emergency.
- Temperature: Most AEDs are rated for storage between 32°F and 122°F. If the cabinet is in a location exposed to extreme heat or cold (near an exterior door, in an unheated garage, or in direct sunlight), consider relocating it.
Step 5: Inspect the Response Kit
An AED alone isn’t enough. The response kit stored alongside the device should contain scissors (to cut through clothing), nitrile gloves, a disposable shaving razor (chest hair prevents pads from making good contact), gauze pads, and a CPR barrier mask. Check that all items are present and that nothing has been borrowed or used without being replaced.
Step 6: Confirm CPR Training Is Current
At least one person at your facility should have a current CPR/AED certification. Monthly checks are a good time to verify this. CPR certifications typically expire every two years, and it’s easy to lose track. Note the certification holder’s name and expiration date on your inspection log.
Keep a Written Log Every Time
Document every monthly check on a standardized form. At minimum, record the date of inspection, the inspector’s name, the status indicator result, the battery installation date, the pad expiration dates, and whether any corrective action was taken. A simple paper checklist kept near the AED cabinet works fine, though some organizations use digital tracking systems.
This log matters for more than just organization. OSHA guidance directs employers to inspect, test, and maintain AEDs in accordance with manufacturer specifications. More importantly, federal liability protections for AED owners can disappear if you fail to properly maintain and test the device. Under the federal AED liability statute, the person or organization that acquired an AED is immune from civil liability for harm resulting from its use, but only if the harm was not due to a failure to properly maintain and test the device. A consistent, documented inspection history is your evidence that you met that standard.
What to Do When Something Fails
If your monthly check reveals a red indicator, a chirping alarm, expired pads, or a low battery warning, act the same day. Low battery messages are not something to address “next month.” Replace the flagged component and run a manual status check (your owner’s manual will explain how to trigger one) to confirm the device returns to a ready state.
If the AED fails its self-test for reasons other than an expired battery or pads, contact the manufacturer. If the unit experienced an unexpected failure during actual use on a patient, report it to both the manufacturer and the FDA’s MedWatch program, then return the unit so the failure can be analyzed. In the meantime, remove the AED from service and make sure staff know it’s unavailable.
A replacement AED or loaner unit from the manufacturer is worth pursuing immediately. Even a short gap in AED availability at your location increases risk, and the whole point of monthly checks is making sure that gap never happens.