LIFEPAK uses a rechargeable lithium battery that can be recharged by connecting the LIFEPAK AED to the Physio-Control CHARGE-PAK battery charger. The battery charger should always remain connected to the Physio Control LIFEPAK AED to ensure that the battery is fully charged and prepared for an SCA medical emergency. The CHARGE-PAK battery charger should be replaced after an SCA event, after 2 years of non-use or when the AED visually indicates with a minus sign that the battery charger needs to be replaced. When replacing the battery in the Physio Control LIFEPAK AED it is important to dispose of the used battery properly. The Physio-Control LIFEPAK CR Plus Battery (11403-000002) replacement kit includes a battery discharger which should be used to completely discharge the AED battery. After discharging the battery, it is ready to be recycled.