This Li/MnO2 battery is specifically designed for the Physio-Control LIFEPAK CR2 AED. It comes with 1 battery and replacement instructions, allowing for 200 joule shocks (with one minute of CPR between shocks) at 20C or 103 360 joule shocks and 800 minutes of operational time. When the device is not used daily, the battery requires replacement after 4 years and the first warning guarantees at least 6 shocks and 30 min of runtime.