Philips HeartStart FRx AED Defibrillator Aviation Battery For Aircraft use. Complies with TSO C-142.The Philips HeartStart FRx AED Aviation Battery Pack is a disposable, lithium manganese dioxide, long-life battery that will typically last for four years with the defibrillator in standby mode. The battery will not deplete until it is inserted in the device. It must be inserted within 5-years of manufacturing date. For use with the Philips HeartStart FRx AED Defibrillator (861304).