LIFEPAK 12 NiCd Battery by Physio-Control. Rechargeable nickel-cadmium. Fuel gauge shows how much battery power is available. Important note: This 1.6 Amp Hour Capacity Battery must be used with an AC or DC Power Adapter which is compatible with 1.6 amp hour batteries. Defibrillator/monitor display screen will show the presence of batteries in the device, along with the remaining battery charge, and will show when the battery is depleted.