Both types decide for themselves whether a shock is needed. The difference is a single moment at the peak of the rescue: who delivers it.
Every modern AED, semi or fully automatic, follows the same core sequence: it guides you through pad placement with voice prompts, analyses the heart rhythm automatically, and will only ever arm a shock when it detects a shockable rhythm such as ventricular fibrillation. Neither type can shock a healthy heart, and both follow resuscitation guidelines from bodies like the NZ Resuscitation Council. If that surprises you, read AED myths busted.
Under extreme stress, some rescuers freeze at the button. They fear hurting the patient, or doubt themselves at the critical moment. Every second of hesitation costs survival odds, because the chance of survival falls 7 to 10% per minute in cardiac arrest. A fully automatic device removes that decision entirely: once the rhythm analysis says shock, the shock happens.
On the other hand, some organisations with trained first aid teams prefer the semi-automatic's explicit human confirmation, and regular training makes hesitation unlikely. Both philosophies are valid; the right choice depends on who your rescuers will be.
| Your situation | Better fit |
|---|---|
| Public spaces, community facilities, retail: rescuer is likely a stranger | Either; semi-automatic is the more common choice |
| Workplaces without designated first aiders | Either; semi-automatic is the common choice |
| Workplaces with trained, practised first aid teams | Either; semi-automatic is the common choice |
| Medical teams and event medics | Semi-automatic, or the AED Pro with manual override |
ZOLL offers the AED Plus in both versions, with identical Real CPR Help® compression coaching, the same one-piece CPR-D-padz® electrode, the same 5 year consumable life and the same rugged IP55 build. The only difference is software: just tell us which mode you want when ordering. The ZOLL AED 3 is also available in semi-automatic and fully automatic configurations.
Still torn? Describe your site and your people on 0800 55 99 55. We will recommend the right mode in one conversation, with no obligation.
One conversation and we will recommend semi or fully automatic for your site.
No obligation. No pressure. Just expert New Zealand advice on saving lives.
