KUALA LUMPUR, Malaysia (AP) — The first comprehensive report into the disappearance of Malaysia Airlines Flight 370 revealed Sunday that the battery of the locator beacon for the plane's data recorder had expired more than a year before the jet vanished on March 8, 2014.

The report came as Australian Prime Minister Tony Abbott said the hunt for the plane would not end even if the scouring of the current search area off Australia's west coast comes up empty.

Apart from the anomaly of the expired battery, the detailed report devoted pages after pages describing the complete normality of the flight, which disappeared while heading from Kuala Lumpur to Beijing, setting off aviation's biggest mystery.

Families of the 239 people who were on board the plane marked the anniversary of the Boeing 777's disappearance, vowing to never give up on the desperate search for wreckage and answers to what happened to their loved ones.

Despite an exhaustive search for the plane, no trace of it has been found. In late January, Malaysia's government formally declared the incident an accident and said all those on board were presumed dead.

The significance of the expired battery in the beacon of the plane's flight data recorder was not immediately apparent, except indicating that searchers would have had lesser chance of locating the aircraft in the Indian Ocean, where it is believed to have crashed, even if they were in its vicinity. However, the report said the battery in the locator beacon of the cockpit voice recorder was working.

"The sole objective of the investigation is the prevention of future accidents or incidents, and not for the purpose to apportion blame or liability," the report said.

Even though the beacon's battery had expired, the instrument itself was functioning properly and would have in theory captured all the flight information.

The two instruments — commonly known as "black boxes" — are critical in any crash because they record cockpit conversations and flight data through the end of a flight.

The 584-page report by a 19-member independent investigation group went into minute details about the crew's lives, including their medical and financial records and training. It also detailed the aircraft's service record, as well as the weather, communications systems and other aspects of the flight. Nothing unusual was revealed, except for the previously undisclosed fact of the battery's expiration date.

The report said that according to maintenance records, the battery on the beacon attached to the flight data recorder expired in December 2012, but because of a computer data error, it went unnoticed by maintenance crews. "There is some extra margin in the design to account for battery life variability and ensure that the unit will meet the minimum requirement," it said.

"However, once beyond the expiry date, the (battery's) effectiveness decreases so it may operate, for a reduced time period until it finally discharges," the report said. While it is possible the battery will operate past the expiration date, "it is not guaranteed that it will work or that it would meet the 30-day minimum requirement," it said.

The report gave insight into the physical and mental well-being of the flight's pilot, Capt. Zaharie Ahmad Shah, saying he had no known history of apathy, anxiety or irritability. "There were no significant changes in his lifestyle, interpersonal conflict or family stresses," it said.