The FR3 disposable, non-rechargeable manganese dioxide battery provides long life with a five year shelf life plus three years of use. It is Lithium ion technology designed solely for the HeartStart FR3 AED. Dispose of properly.Philips provides a three year warranty on the battery or 300 shocks, or 12 hours of monitoring time.You can see the ''Install Before Date'' on the battery. This is not the expiration date. It means if you store the battery in plastic until the ''Install Before Date'' Philips warrants that you will get three years of use, or 300 shocks from the battery.The best way to know how long your battery has been installed is to mark the installation date on the battery when you put it in service with a Sharpie.