This universal base charger by Physio-Control supports adapter trays for the LIFEPAK 12 and LIFEPAK 15 Li-ion batteries. Features Include Up to 12 hours of monitoring with two batteries. Charges up to 80 capacity in just 2 hours, 100 in just over 4 hours. Maintenance free - new LIFEPAK Li-ion batteries require no conditioning or calibration. Items Sold Separately AC power cord 11140-000115 LIFEPAK 12 Battery Adapter Tray 11141-000116 or LIFEPAK 15 Battery Adapter Tray 11140-000052 LIFEPAK 12 Li-ion battery 11141-000106 or LIFEPAK 15 Li-ion Battery 21330-001176