Automated External Defibrillators (AEDs) are designed to restore a normal heart rhythm in cases of sudden cardiac arrest (SCA). Choosing the right AED model is important because design, maintenance requirements, and features vary across devices.

This article compares two widely used AEDs: the ZOLL AED Plus and the Heartsine Samaritan PAD 360P. Both are intended for use by laypeople and trained responders, but they take different approaches. ZOLL places emphasis on real-time CPR feedback, while Heartsine focuses on compactness, durability, and simplified maintenance.

Design & Portability

ZOLL AED Plus
The ZOLL AED Plus is a larger and heavier unit, weighing around 3.1 kg. Its dimensions are approximately 13.3 cm × 24.1 cm × 29 cm, making it one of the bulkier portable defibrillators on the market. The size is not usually an issue in workplaces or indoor public areas, but it may be less convenient in situations where portability is a priority.

Heartsine Samaritan PAD 360P
In contrast, the Heartsine Samaritan PAD 360P is compact and lightweight, weighing just 1.1 kg. Its size is roughly 20 cm × 18 cm × 2.5 cm, allowing it to fit easily into smaller cabinets or carry cases. This makes it well suited to community installations, schools, or locations where space is restricted.

Observation
In practice, the smaller size of the Heartsine makes it more visible in wall cabinets with clear signage, whereas the bulkier ZOLL model is often kept in larger storage bags with accessories.

Durability & Protection Ratings

ZOLL AED Plus
The ZOLL AED Plus carries an IP55 rating, which means it is protected against limited dust ingress and water jets from any direction. It has also been tested for drops up to 1.5 metres, making it suitable for use in workplaces, offices, and many public settings. While durable, it is not optimised for harsher outdoor conditions without an additional weatherproof cabinet.

Heartsine Samaritan PAD 360P
The Heartsine Samaritan PAD 360P offers a slightly higher IP56 rating, giving it improved resistance to dust and powerful water jets. It is also tested for shock and vibration resistance, making it particularly reliable in outdoor or mobile environments such as sports facilities, community cabinets, or emergency service vehicles.

Did You Know?
An IP56-rated AED like the Heartsine PAD 360P can better withstand exposure to rain if deployed in an unlocked outdoor cabinet — a situation sometimes found in rural villages and sports grounds.

Battery & Electrode Management

ZOLL AED Plus
The ZOLL AED Plus uses a system of 10 disposable lithium batteries (Duracell 123A). These typically last around 5 years in standby mode. The electrodes, known as CPR-D-Padz, also have a 5-year shelf life. Paediatric use requires a separate set of Pedi-Padz, which need to be stored alongside the device and replaced when expired. This setup ensures long life but means there are multiple consumables to monitor and replace.

Heartsine Samaritan PAD 360PThe Heartsine PAD 360P uses an all-in-one cartridge called a Pad-Pak, which combines both the battery and electrodes. The Pad-Pak has a 4-year shelf life and comes in two versions: adult and paediatric. This simplifies maintenance because only one item needs to be checked and replaced at expiry, reducing the risk of mismatched batteries and pads.

Observation
In many community settings, volunteers report that checking a single Pad-Pak is easier than monitoring both batteries and electrodes separately, especially where responsibility is shared between several people.

Ease of Use & CPR Guidance

ZOLL AED Plus
The ZOLL AED Plus is known for its Real CPR Help® technology. This provides real-time feedback on both the rate and depth of chest compressions. The device uses voice prompts, a metronome, and visual indicators to guide the responder. If compressions are too shallow, the device prompts with “Push harder.” This feature helps maintain high-quality CPR, even for rescuers with limited training.

Heartsine Samaritan PAD 360P
The Heartsine PAD 360P provides clear audio and visual prompts, including a metronome for compression timing. However, it does not measure compression depth. Instead, it focuses on keeping instructions simple and straightforward, with fully automatic shock delivery to reduce user hesitation.

Observation
In workplaces where trained first aiders are present, the ZOLL’s feedback system may improve resuscitation quality. In contrast, the Heartsine’s simplicity makes it more approachable in community settings where responders may never have practised CPR.

Shock Delivery & Technology

ZOLL AED Plus
The ZOLL AED Plus uses a biphasic truncated exponential (BTE) waveform. It delivers escalating energy shocks, typically starting at 120 joules, then increasing to 150 joules and 200 joules for subsequent shocks. In paediatric mode, the energy is reduced to levels suitable for children. This escalation helps adapt to different patient needs while maintaining safety.

Heartsine Samaritan PAD 360P
The Heartsine PAD 360P employs a proprietary SCOPE™ biphasic waveform. This automatically adjusts the energy and waveform to suit the patient’s impedance (the resistance of the chest to electrical current). While it delivers lower energy shocks compared to some models, clinical studies support the effectiveness of impedance-compensated waveforms. The PAD 360P always delivers shocks automatically when required, without requiring a button press.

Warranty & Cost of Ownership

ZOLL AED Plus
The ZOLL AED Plus is supplied with a 5-year warranty, which can often be extended to 7 years upon registration. Its batteries and adult pads last for up to 5 years, meaning fewer replacements are required during that period. However, consumables are purchased separately, and paediatric pads add an additional ongoing cost if required.

Heartsine Samaritan PAD 360P
The Heartsine Samaritan PAD 360P comes with a longer 8-year warranty as standard. Its Pad-Pak consumables need replacing every 4 years, covering both electrodes and battery in one unit. This simplifies procurement and typically reduces servicing complexity, though the interval is slightly shorter than ZOLL’s components.

Best Use Cases for Each Device

ZOLL AED Plus
The ZOLL AED Plus is best suited to workplaces, schools, and larger organisations where trained staff are available or where responders may benefit from detailed CPR guidance. Its real-time compression feedback makes it especially useful in environments where quality CPR can be maintained until professional help arrives. The larger size is less of an issue in fixed indoor installations.

Heartsine Samaritan PAD 360P
The Heartsine PAD 360P is ideal for community settings, sports clubs, and outdoor environments. Its lightweight and compact design makes it easier to store in smaller cabinets or transport in mobile kits. With an IP56 rating and combined battery/pad cartridge, it is also a practical choice for villages, outdoor sports venues, or locations without dedicated maintenance teams.

Did You Know?

Public access defibrillators (PADs) are now installed in more than 50,000 locations across the UK according to the British Heart Foundation. Many are stored in outdoor cabinets, meaning environmental resistance (such as the IP rating) is a key factor when selecting a device.

Observation
In some outdoor cabinets, condensation build-up can reduce visibility of the AED inside. Compact units like the Heartsine PAD 360P are often easier to spot through the window than bulkier devices such as the ZOLL AED Plus.

Conclusion

Both the ZOLL AED Plus and the Heartsine Samaritan PAD 360P are reliable, clinically validated AEDs, but they are designed with different priorities in mind.

The ZOLL AED Plus stands out for its real-time CPR feedback, helping rescuers deliver effective compressions. It is well suited to workplaces, schools, and environments where responders may benefit from advanced prompts.
The Heartsine PAD 360P is valued for its lightweight design, high durability, and simplified maintenance. It is often chosen for community and outdoor settings, where resilience and ease of upkeep are essential.

Ultimately, the right choice depends on where the AED will be located and who is most likely to use it.