If you need to turn off an AED, the method depends on the brand, but most models power off by pressing and holding the power button for several seconds or by closing the lid. For the Philips HeartStart, press and hold the green on/off button. For the Zoll AED Plus, press and hold the shock button until it powers down. For Physio-Control LIFEPAK models, press and hold the on/off button. For Cardiac Science Powerheart, close the lid or press and hold the button. For Defibtech, press and hold the button. For HeartSine Samaritan, close the cover or press and hold the on/off button. The more important question is when to turn it off — never do so during an active rescue unless emergency medical services arrive and instruct you to stop.
When should you turn off an AED during a rescue?
You should almost never turn off an AED while a patient is unresponsive or in cardiac arrest. The device gives step-by-step voice prompts. Follow them until emergency medical services (EMS) arrive and take over.
The only safe times to turn off an AED during an emergency are:
- When a trained EMS professional tells you to stop.
- When the patient wakes up, starts breathing normally, and the device confirms no shock is needed.
- When the scene becomes unsafe — for example, flooding, fire, or dangerous electrical hazard.
In most real cardiac arrest situations, you leave the AED on. The device continues to monitor the heart rhythm and may advise additional shocks. Turning it off early can delay lifesaving care.
How to turn off a Philips HeartStart AED (FRx, OnSite, FR3)
Philips HeartStart models use a single green button. To turn the device on, press it once. To turn it off, press and hold the same button for about two seconds.
You will hear a voice prompt confirming the device is shutting down. If the device is mid-analysis or mid-shock, pressing the button will not immediately turn it off — the device completes its current cycle first. This is a deliberate safety feature.
The Philips HeartStart also powers down automatically after about 30 minutes of inactivity. Do not rely on this during a live rescue. Hold the button down when EMS instructs you to stop.
How to turn off a Zoll AED Plus
The Zoll AED Plus has a single power button on the top of the device. Press and hold it for several seconds to turn off the AED.
Like Philips, the Zoll will not shut down mid-analysis. It completes the ongoing rhythm check or delivers the shock if already charging. Only then will it power off.
Some older Zoll AED Plus models have an on/off switch on the side rather than a single button. Check the side panel if the top button does not work. If you encounter a model with a hard switch, simply toggle it to the off position.
How to turn off a Physio-Control LIFEPAK AED (CR Plus, 1000, 500)
Physio-Control (now part of Stryker) makes several AED models. Each works slightly differently.
For the LIFEPAK CR Plus: Press and hold the on/off button located above the shock button. The device will power down after a few seconds. Closing the lid on some models also turns it off.
For the LIFEPAK 1000: Press and hold the on/off button. The screen will go blank, and the device will stop voice prompts. This model also has a manual mode for advanced users. In manual mode, turning off the device requires pressing and holding the same button.
For the LIFEPAK 500: Press and hold the on/off button. The device will shut down after completing any active analysis or shock cycle.
A common feature across LIFEPAK devices: they will not turn off during a shock delivery. The device waits until it is safe to power down.
How to turn off a Cardiac Science Powerheart AED (G3, G5)
Cardiac Science Powerheart AEDs turn off when you close the lid. This is the primary power-down method for these models.
If the lid is already open, press and hold the yellow on/off button. The Powerheart G5 has a dedicated button marked with the power symbol. Hold it for about two seconds.
Powerheart devices have a “rescue ready” light that blinks when the unit is on. When the lid is closed or the button is held, the light stops blinking and the device powers down safely.
Do not open the lid again immediately after turning it off — the device will restart its self-test and voice prompts.
How to turn off a Defibtech Lifeline AED
Defibtech Lifeline AEDs have a single orange on/off button. Press and hold it to turn the device off.
The button is large and located on the front of the unit. The device gives a voice prompt confirming shutdown. If the AED is analyzing a rhythm or delivering a shock, it will complete that action before powering down.
Some Defibtech models also have a carrying case with a zipper. Unzipping the case opens the protective flap. Closing the fully unzipped case does not turn off the device on all models — you must use the button.
How to turn off a HeartSine Samaritan AED (PAD 300, 350, 360P, 500P)
HeartSine Samaritan AEDs turn off by closing the lid of the carrying case. This is the most convenient method for these compact units.
If the lid is already open and you need to power down manually, press and hold the on/off button marked with the power symbol. Hold it for about three seconds until you hear a confirmation tone or voice prompt.
HeartSine models also have a backup turn-off method: remove the battery pack. Only do this if the device will not respond to the button or lid. Removing the battery stops all functions immediately. Reinsert the battery only after confirming you need to use the device again.
What happens if you turn off an AED by mistake?
If you accidentally turn off the AED during a rescue, turn it back on immediately. The device restarts its analysis from the beginning. This causes a delay of 10 to 20 seconds while the device reinitializes, checks its internal status, and begins a new rhythm analysis.
No permanent harm is done to the device or the patient from one accidental shutdown. But repeated accidental shutdowns add up. Each restart delays shock delivery. In cardiac arrest, every minute without defibrillation reduces survival chances by about 7 to 10 percent.
To avoid mistakes, keep the AED on until EMS arrives. Do not let bystanders handle the device during the rescue. Place it on the patient’s left side, away from foot traffic, and follow voice prompts.
Common myths about turning off AEDs
A myth circulates that you should turn off the AED after a shock is delivered. This is false. The AED continues to monitor the heart after a shock. It will advise if another shock is needed or if CPR should continue. Turning it off stops this monitoring.
Another myth claims that AEDs can be turned off by removing the electrode pads. This is also false. Removing the pads causes a “pads off” warning or error message, but the device stays powered on. You must use the power button or lid to turn off the device.
Some people believe AEDs automatically turn off after delivering the maximum number of shocks. This is not true for most brands. Philips, Zoll, LIFEPAK, Cardiac Science, Defibtech, and HeartSine AEDs remain on indefinitely during a rescue unless manually turned off or the battery dies.
Does turning off an AED erase data from the rescue?
No. AEDs store clinical data including heart rhythm recordings, shock delivery times, and device events in internal memory. Turning off the device does not erase this information.
Data remains saved even if the battery is removed. Paramedics or hospital staff can later download the data using a USB connection or memory card. This information helps clinicians understand the patient’s heart rhythm during the arrest and the timing of interventions.
If you are turning off the AED because EMS has arrived, leave the device on for an extra moment so the responding team can check that the data is intact. Then power it down per the specific brand instructions.
Key safety warning about AED ownership and training
AEDs are designed for use by untrained bystanders. Voice prompts guide every step. But turning off an AED at the wrong time can delay care. Anyone who owns or manages an AED in a workplace, school, or community setting should receive formal training. Training covers when to turn off the device and when to leave it powered on.
The American Heart Association recommends refresher training every two years for AED users. If you are responsible for an AED, check the manufacturer’s guidelines for your specific model. Some brands have additional shutdown procedures for maintenance or storage that differ from emergency shutdown.
If you are purchasing an AED and comparing brands, consider the power-down method as part of your evaluation. Models that require holding a button for several seconds are harder to turn off accidentally than models that turn off by simply closing the lid.
Frequently Asked Questions
Can you turn off an AED while it is analyzing the heart rhythm?
Most AEDs will not immediately power off during analysis — they complete the current analysis first, then shut down. Do not attempt to turn it off during analysis unless EMS instructs you to stop.
Does removing the battery turn off an AED?
Yes, removing the battery immediately powers down any AED, but it also stops all monitoring and may erase real-time clock data. Use the power button or lid instead unless the device is unresponsive.
How long does an AED stay on after use?
Most AEDs stay on indefinitely during an active rescue unless manually turned off, the battery dies, or the device enters a low-power sleep mode after 30 minutes of inactivity (Philips HeartStart models specifically).
Will turning off an AED reset its internal clock or data?
No, the rescue data and clinical recordings remain saved in internal memory after shutdown, and the clock continues running via an internal backup battery on most models. Only removing the main battery for an extended period may affect the clock.
