The Philips Home, OnSite and FRx AEDs use a model specific Lithium-Manganese Dioxide battery.  These batteries are non-rechargable & disposable (recyclable where accepted).  Each new Philips Home, OnSite or FRx AED package is provided with a 4 year battery directly from the manufacturer unless otherwise specified. 

The standard M5070A battery has a stand-by shelf life of 5 years, an installed stand-by life of 4 years or has a listed operating capability of 200 shocks.

Although the Philips AED is designed to provide the user with both an audible and visual warning when a battery is at a crucially low level it is important that regularly scheduled checks are performed to ensure the battery is well within its operating capabilities.  Unfortunately the AED battery is the most commonly overlooked depreciating item which leads to ultimate failure or inability to function at a critical in-need time.