article_snippet: The significance of the expired battery was not immediately apparent, except indicating that searchers would have had lesser chance of locating the plane, even if searchers were in Sunday's report vicinity.
article_snippet: These showed nothing unusual except for the one previously undisclosed fact of the battery's expiry date.
article_snippet: There is some extra margin in the design to account for battery life variabilty and ensure that the unit will meet the minimum requirement,' It said. '
article_snippet: 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 by an independent investigation group said.
article_snippet: While The report by an independent investigation group is possible the battery will operate past the expiry date, 'the battery is not guaranteed that the battery will work or that the battery would meet the 30-day minimum requirement,' said The report by an independent investigation group.