How Long Does an AED Battery Last?

AED batteries are the source of the electric shock used to reverse sudden cardiac arrest, which is why it’s so critical to understand AED battery life and ensure that replacement batteries are available. While battery life varies between manufacturers and models, AED batteries typically last anywhere from two to seven years and should always be replaced before they expire.

AED Battery Lifespan by Make and Model

Use this quick guide to find the life expectancy of your automated external defibrillator battery:

The actual life expectancy of AED batteries is affected by the ambient temperature and whether or not the battery has been installed. Other factors such as relative humidity and short-circuits can also affect battery life.

When multiple batteries are used together—such as with the ZOLL AED Plus, all of the batteries must be replaced at the same time. Leaving some of the used batteries in and pressing the “reset battery” button could result in a false Ready status without sufficient charge for a complete rescue.

Important note: When replacing batteries, it’s critical to use original manufacturer batteries that are compatible with the AED model you have. Using batteries other than the ones that are recommended for your defibrillator can void your warranty and put patients’ lives at risk.

How to Check Your AED Battery’s Expiration Date

Expiration dates are calculated in three main ways, depending on which automated external defibrillator model you have.

Manufactured Date

Most AED batteries come with a “manufactured date” printed on the label. This date is especially helpful in cases when the battery expires after four years installed or five years uninstalled because you can calculate both from this date. To get the full four years of “installed” battery life, you usually need to install the battery within one year of the date of manufacture.

Install By Date

Some portable defibrillator batteries come with an “install by date” rather than an expiration date. As long as you install the batteries by this date, you can be assured of the full “installed” battery life (usually four years).

Expiration Date

Other batteries come with an expiration date, which presumes that the batteries are installed right away. In cases such as the Defibtech long-life battery (which is often purchased as a backup), the maximum shelf life is seven years, after which the battery expires.

Understanding Shelf Life

As a general rule, the shelf life of a battery (uninstalled) refers to the time after which the operating time will begin to reduce. However, it’s essential to replace the battery before the shelf life expires rather than installing it at that point and starting to count “installed” years from there as the battery’s capacity and performance will be compromised, putting patients’ lives at risk.

AED Pads Expire, Too

Just like defibrillator batteries, electrode pads expire too. Over time, the conductive adhesive gel on the pads dries out and they no longer stick or conduct electricity effectively. The life expectancy of AED pads varies but is generally between two and four years.

According to an extensive review of AED failures, around 23% of defibrillator failures were due to problems with the batteries and 23% were due to problems with the pads. Adding those percentages together, we can see that up to half of the AED-failure-related deaths could be prevented by replacing the batteries and pads before they expire. It’s also advised to have a replacement battery ready in case your in-date battery malfunctions or a rescue takes longer than expected.

Expiration Reminders and AED Program Management

Once you have acquired an automated external defibrillator, there are several ways to keep track of battery life.

1. Write the manufactured date, install by date, or expiration date on the inspection tag.\
2. Fulfill all AED maintenance requirements mandated by your state, including monthly checks to ensure that the unit is ready to use and the batteries aren’t running low.
3. Set battery and pad replacement reminders for yourself. These could be written on a calendar or automated using AED management software.
4. Sign up for AED program management with your authorized defibrillator retailer for comprehensive support in managing expiration dates, AED training requirements, and other AED program details like signage and reporting.

What to Do with an Expired Battery

Expired AED batteries should be taken to your local battery recycling or hazardous waste facility. They should not be thrown in the general trash as they can cause fires. Furthermore, lithium—one of the main ingredients in Li-ion batteries—is a mined resource with growing demand. When you recycle your expired batteries, the lithium can be recovered and used again.

A Working Battery Is Key to a Successful Rescue

AED batteries last for a long time stored in the case or installed with the device on standby mode, but their capacity and performance do decline over time—potentially making them ineffective when you need them most. To ensure you’re always rescue-ready:

1. Only use the battery recommended by the manufacturer.
2. Follow all of the manufacturer’s instructions for battery storage and installation.
3. Set reminders for routine checks and battery replacement or sign up for AED program management.
4. Keep a spare battery with your AED in case of malfunction or a long rescue.

Initially, it can take a bit of work to get used to performing routine checks and replacing your AED batteries (and pads) every few years. However, once you do, it will become a normal part of your home, business, or institution’s operations. A working AED with working batteries and pads is the only kind that can save a life. Make sure that this includes yours.