How to Replace an AED's Electrode Pads and Battery

The defibrillator's daily self-test signals a problem with a red light or an audible alert when the electrode pads or battery are close to their expiry date. This date also appears directly on the electrode pad packaging and on the battery label, shown as a month and a year. Do not wait for the unit's alert before checking these dates: a regular visual check, logged in the safety register, makes it possible to order consumables in advance and avoid the device becoming unavailable.

Before unwrapping new electrode pads, switch the defibrillator off or wait for it to enter standby mode. The model and reference of the pads must match exactly what the manufacturer specifies, since an incompatible connector simply will not plug in. On sites used by children, pediatric electrode pads should be ordered and stored next to the adult ones, clearly labelled, as the two are never interchangeable. The same care applies to the battery, whose reference is printed on the manual or on the old battery being removed.

The used electrode pad cartridge usually detaches with a simple push or by sliding a tab, with no tools needed. The new sealed cartridge clicks into place, connector facing the right way. The pouch should stay sealed until it is actually used on a patient: once opened to the air, the conductive gel dries out and the pads lose their effectiveness even before the printed expiry date. After fitting, the device automatically runs a self-test that confirms the new pads have been recognised correctly, shown by the light turning green again.

The battery compartment usually opens with a latch or a single screw, without needing to fully dismantle the casing. The old battery slides out by pulling a tab, and the new one slides in until it locks firmly into place, audibly or by feel. On some models, the device needs a few seconds to initialise before its ready light comes back on: it should not be switched off or on again during this phase. If the light stays red after replacement, the battery is more likely poorly seated than faulty, and simply needs repositioning.

Reusing an electrode pad cartridge that has already been opened, even briefly, means fitting a partially expired consumable without realising it. Mixing a battery or pads from a different brand than the one recommended by the manufacturer can stop the device working or void its warranty. Forgetting to check that the light has returned to green after the operation is another common mistake, since a defibrillator can display a silent alert if the fitting was not recognised correctly. Finally, storing spare consumables somewhere too hot or too humid speeds up their deterioration before they are even installed.

Every replacement of electrode pads or a battery should be logged in the site's safety register, with the date, the reference of the consumable fitted and the name of the person who carried it out. Used batteries follow the standard battery and accumulator collection scheme, available at recycling centres or through the defibrillator supplier. Electrode pads that were never used on a patient can go out with household waste, while those used during an actual intervention follow the healthcare waste disposal route. A maintenance contract that includes consumable renewal takes this organisation off the operator's hands, with rental available from 50 euros a month excl. VAT.