Is Your AED Expired? How to Read Date Codes (Philips, Defibtech, & Zoll)

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Philips HeartStart OnSite Pads (M5071A) expiration date label with hourglass symbol
Be A Hero Blog
December 11, 2025 0 Comments

Introduction

You bought an AED five years ago to protect your business. It’s been sitting in the cabinet ever since. The light is blinking green… so it’s fine, right?

Not necessarily.

One of the biggest risks in AED ownership is “Silent Expiration.” Batteries and pads expire on different schedules, and manufacturers often use confusing date codes (like “Manufacture Date” vs. “Install-By Date”) that make it hard to know if you are compliant.

If you interpret these dates wrong, you might throw away a good battery—or worse, rely on a dead one during an emergency.

Here is the definitive guide to cracking the code on your AED expiration dates.

1. The Universal Symbol: The “Hourglass”

Before we look at batteries, let’s look at your Pads. Almost every AED pad (electrodes) uses the international “Hourglass” symbol.

  • Look for: An hourglass icon next to a date (YYYY-MM-DD).

  • What it means: This is a Hard Expiration Date.

  • The Rule: If today’s date is past the date next to the hourglass, the pads are dead. The conductive gel has likely dried out and they will not adhere to a patient’s skin or deliver a shock.

Need new pads?

2. Philips HeartStart (The “Install-By” Confusion)

Philips batteries (for OnSite, Home, and FRx units) are the most confusing because they list an “Install-By” date, not an expiration date.

  • The Code: You will see a large date printed on the battery labeled “Install Before.”

  • What it means: This is the Shelf Life. It is NOT the expiration date.

  • The Math: You have until that date to put the battery into the machine. Once you install it, it is good for 4 Years from that moment.

  • The Problem: If you never wrote down the date you installed it, you have no way of knowing when the 4 years are up.

  • The Solution: If you don’t know when you installed it, or if the “Install Before” date was more than 5 years ago, play it safe and replace it.

Get a Fresh Philips M5070A Replacement ($129)

3. Defibtech Lifeline (The 5-Year Clock)

Defibtech batteries (the yellow pack) generally use a Manufacture Date.

  • The Code: Look for a sticker with a date in YYYY-MM-DD format.

  • The Math: The standard yellow battery (DBP-1400) has a 5-Year Standby Life.

    • Take the date on the sticker -> Add 5 Years.

    • Example: If the sticker says 2020-01-15, the battery expired on 2025-01-15.

  • The Hidden Trap: Don’t forget the 9V Battery! There is a 9-volt lithium battery inside the main pack that powers the self-tests. If your unit is chirping, check the 9V first.

  Stop Guessing  Expiration Dates: Buy the Defibtech DBP-1400 battery pack

4. Cardiac Science Powerheart (G3 & G5)

Cardiac Science batteries (the big yellow or orange slides) typically show a Manufacture Date.

  • The Code: Printed clearly on the label (e.g., “2021-06”).

  • The Math: These batteries have a 4-Year Full Operational Guarantee from the time of installation.

  • The Rule: Just like Philips, if you didn’t write the installation date on the tracking card, you should calculate 4 years from the Manufacture Date to be safe.

Shop Powerheart G3 Battery ($229) | Shop Powerheart G5 Battery ($239)

5. ZOLL AED Plus (The “Sleeve” Trick)

ZOLL units use consumer lithium batteries (Type 123), which makes checking them tricky.

  • The Code: You have to look at the batteries themselves.

  • The Math: ZOLL batteries and pads both last 5 Years.

  • The Advice: If you are changing the batteries, you should almost certainly change the pads (CPR-D Padz) at the same time. Keep them on the same 5-year cycle to avoid confusion.

Shop Fresh ZOLL Batteries

Summary Checklist

Go check your AED right now.

  1. Pads: Is today’s date past the “Hourglass” date? (Replace Immediately).

  2. Battery: Has it been installed for more than 4 years? (Replace Immediately).

  3. Status Indicator: Is it flashing Green? (If Red or Beeping, Troubleshoot Immediately).

A dead battery can’t save a life. If you are unsure about your dates, our team at AEDLand can help you decode them.

Disclaimer

The information provided in this guide is for general informational and educational purposes only. While we strive to provide accurate and up-to-date information regarding AED maintenance and date codes, manufacturers may change their labeling, lifespan guarantees, or technical specifications at any time. This guide is not a substitute for the official manufacturer’s user manual or guidelines.

AEDLand (and its parent entities) assumes no responsibility or liability for any errors or omissions in the content of this site. The user is solely responsible for ensuring their life-saving equipment is maintained in accordance with the manufacturer’s requirements and local laws. Use of this information is at your own risk.