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Keeping a defibrillator ready
Self-test lights, pad and battery expiry dates, the monthly walk-past, and the organisational failure behind most dead devices: nobody was named as the person responsible for it.
CPR in sixty seconds
- Unresponsive and not breathing normally? Gasping is not breathing. Treat it as a cardiac arrest.
- Call 112 (113 in Norway). Speaker on, phone on the floor. Stay on the line — the dispatcher will coach you.
- Push hard and fast in the centre of the chest: 5–6 cm in an adult, 100–120 per minute, letting the chest come all the way back up.
- Send somebody else for a defibrillator. Do not go yourself unless it is seconds away. Keep compressing.
- Turn the device on and do what it says. It decides whether to shock. After a shock, go straight back to compressions.
This is a reference written for bystanders, not a diagnosis, a training course or medical advice. It cannot tell you what is wrong with a particular person, and it does not replace the dispatcher on the other end of an emergency call — they can see what is near you and they will talk you through it. If you are worried about your own heart, or about a symptom, that is a conversation with a clinician rather than a page on a website.
The device checks itself, but only itself
Every modern public-access defibrillator runs an automatic self-test — daily, weekly or monthly depending on the model — covering its internal electronics, the battery charge and, in most models, whether the pads are connected and within date. It reports the result with a status indicator: a green light or a moving symbol for ready, a red light, a cross or an audible chirp for a fault. What it cannot check is whether the cabinet is locked, whether the sign has fallen off, whether somebody borrowed the scissors, or whether the device is still on the wall at all.
The monthly walk-past
Someone walks to the device once a month and looks at five things. Is it there. Is the status indicator showing ready. Are the pads sealed, in date and still attached to the connector. Is the battery in date. Is the response kit complete and the cabinet clean, unobstructed and correctly signed. Write the date and the initials on a card in the cabinet. The whole thing takes two minutes and it is the difference between a device and a decoration.
Expiry dates are printed for a reason
Electrode pads contain a conductive gel that dries out; expired pads adhere poorly and may not conduct properly. The date is printed on the sealed pouch. Batteries have a standby life and lose capacity whether or not the device is used. Replace both when the printed date arrives, not when the device complains, and set a calendar reminder a month ahead — a device with expired pads usually still shows a green light until close to the limit, which is exactly what makes it dangerous.
After any use, however brief
A device that has been switched on and applied to a patient goes out of service until it has been reset: fit a new set of pads, check or replace the battery, wipe the case down, and check the internal event recording has been offloaded if your ambulance service asks for it. Do this the same day. A used device put back in the cabinet with the old pads still attached is one of the more common ways a public defibrillator fails when it is next needed.
The organisational failure behind most dead devices
Audits of public-access devices repeatedly find the same picture: a proportion are unusable, and the reason is almost never technical. The device was donated by a club that dissolved, the caretaker who checked it retired, the shop changed hands, the building was refurbished and the cabinet was moved to a store room. The fix is administrative. Name a person and a deputy, put the check in a recurring calendar with an owner rather than a team, put the expiry dates in that calendar too, and update the national register entry every time any of it changes.
| Check | What good looks like |
|---|---|
| Device present | In the cabinet, on the wall, where the register says it is |
| Status indicator | Green or the ready symbol; no chirping, no cross |
| Pads | Sealed, in date, connected, spare set if you keep one |
| Battery | Within its printed expiry, correctly seated |
| Cabinet and access | Unobstructed, clean, correct code, alarm working, heating on if outdoors |
| Signage | Sign at the device and directions from the entrance |
| Response kit | Scissors, razor, towel, gloves, mask present |
| Register entry | Location, hours, access and contact still true |
Sources: European Resuscitation Council · Danish Heart Foundation (Hjerteforeningen) on defibrillators · checked 2026-09-08
Frequently asked questions
How often should a public defibrillator be checked?
At least monthly by a named person, in addition to the automatic self-test the device runs on its own. The manual check catches the things the device cannot see, such as a locked cabinet or a missing sign.
How long do pads and batteries last?
Typically two to five years depending on the model, with the date printed on the pad pouch and the battery. Replace on the printed date, and replace pads immediately after any use.
The green light is on but the pads expired last month. Is it usable?
Treat it as out of service and replace the pads today. In a genuine emergency you would still use it rather than nothing, but expired gel adheres and conducts poorly and this is a failure of the monthly check.
How the system around it works
The chain of survival, link by link
Recognition and a call, early CPR, early defibrillation, advanced care and recovery. What each link is actually worth, which one the public owns, and where the chain breaks in practice.
What the survival numbers actually say
Roughly one in ten survives an out-of-hospital cardiac arrest, and the spread between towns is wider than the spread between treatments. How to read the statistics without being misled by them.
National registers, and getting your device into one
A defibrillator the dispatcher cannot see barely exists. What a national register is, which one is the real one in each country, why registration is free, and the paid look-alikes to avoid.
Volunteer responder systems
Denmark, Sweden and Norway alert trained volunteers by phone to arrests near them — one to fetch the defibrillator, one to start compressions. How the systems work, who can join, and what happens when your phone goes off.
Where public defibrillators actually are
The green sign with the heart and the lightning bolt, the places that reliably have one, the cabinets that are locked and the ones that are not, and what to do when you have thirty seconds to decide whether to go looking.
Everything on this subject
Before the emergency, there is a long quiet stretch
Blood pressure, resting heart rate, movement and sleep are the part of this you can act on for years beforehand. TempoLife keeps them in one place, free to start.