Most AEDs turn off by pressing and holding the On/Off button for one to two seconds. The exact method varies slightly by brand, but every modern AED uses some version of a dedicated power button, and none will lose their recorded data when you power them down. Here’s how to do it on the most common models and when it’s appropriate.
The General Method for Any AED
Nearly all AEDs follow the same basic pattern: locate the On/Off button (the same one used to turn it on) and press and hold it. The hold time is typically one to two seconds. The device will beep or give a voice prompt confirming it has powered down. This works whether the AED is analyzing a heart rhythm, waiting for you to press the shock button, or sitting idle between analysis cycles.
If you’re ever unsure which button to press, look for the universal power symbol (a circle with a vertical line at the top). On most units, it’s the largest or most prominent button on the front panel aside from the shock button.
Instructions by Brand
Philips HeartStart FRx
Press and hold the On/Off button for at least one second. The device returns to standby mode, meaning it stays ready for future use as long as a battery is installed. If the AED has charged and is ready to deliver a shock, holding that button for one second also disarms it. The FRx will also disarm itself automatically if you don’t press the shock button within 30 seconds, if the patient’s rhythm changes to one that doesn’t need a shock, or if the battery is removed.
Defibtech Lifeline (DDU-2000 Series)
Press and hold the On/Off button for approximately two seconds. The unit will emit a beep and power off. This works at any point during use, including while the device is charging or preparing to deliver a shock. Holding the button for two seconds immediately disarms the device and shuts it down. If you need to fully disconnect it, push the battery pack eject release latch and pull the battery out.
Zoll AED Plus
Press the On/Off button briefly to power the unit off. Be careful not to hold the button for longer than five seconds, because a long press on the Zoll AED Plus initiates a self-test or data communication mode rather than simply shutting down.
When to Turn Off an AED
During an active rescue, the general rule is to leave the AED on and the pads attached until emergency medical services arrive and take over. The device continuously monitors the patient’s heart rhythm between analysis cycles, and removing it too early means losing that monitoring. EMS providers will tell you when they’re ready to switch to their own equipment.
There are a few situations where turning the AED off makes sense:
- EMS has arrived and paramedics have connected their own monitor or defibrillator to the patient.
- A medical professional has called the resuscitation and all efforts are being stopped. Formal termination-of-resuscitation protocols guide this decision, and it’s not something a bystander should decide alone.
- The AED was activated by mistake and no patient needs it.
- Training or maintenance is complete and the device needs to be returned to its case or wall mount.
If the AED is advising “no shock,” that doesn’t mean you should turn it off. It means the device didn’t detect a rhythm that responds to defibrillation, but the patient may still need CPR and ongoing monitoring. Keep the pads on and the AED running.
Your Data Is Safe After Power Down
AEDs record the patient’s heart rhythm data and event details (timestamps, shocks delivered, and in some models audio) to internal memory. Turning the device off does not erase this information. EMS and hospital staff can download the data afterward to review what happened during the rescue. This record is valuable for the patient’s ongoing care, so there’s no need to worry about losing it by shutting the device down when the time comes.
If the Button Doesn’t Work
On rare occasions a malfunctioning AED may not respond to the power button. In that case, removing the battery is the most direct way to shut it down. On the Defibtech Lifeline, for example, you push the battery eject latch and slide the battery pack out. On most other models, the battery compartment is on the back or bottom of the unit and requires pressing a release tab. Removing the battery immediately cuts power and disarms any pending shock. Once you’ve done this, the AED should be flagged for service before being returned to its storage location.