KUALA LUMPUR, Malaysia - 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 page after page to describing the normality of the flight, which disappeared while heading from Kuala Lumpur to Beijing.

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 search for wreckage and answers to what happened to their loved ones.

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 a 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.

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.

The 584-page report by a 19-member independent investigation group went into minute detail 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 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.

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.

Meanwhile, family members of the passengers and crew aboard the plane marked the anniversary of the plane's disappearance. Voice 370, a support group for the relatives, hosted a "Day of Remembrance" at a mall in Kuala Lumpur with songs, poems, and prayers.

"It is important to highlight to the public that we still don't have any answers and that we must pursue the search," said Grace Subathirai Nathan, whose mother, Anne Daisy, was on the plane.

"The lack of answers and definitive proof - such as aircraft wreckage - has made this more difficult to bear," Malaysian Prime Minster Najib Razak said in a statement.