After 23 days since flight MH370 went missing, the aircraft's black box transmitter battery has an approximate life of only seven days left, and it is now crucial for the pinger locator to head out to the search area.

According to Commodore Peter Leavy of the Royal Australian Navy, the Australian Defence Vessel (ADV) Ocean Shield is being fitted with a Towed Pinger Locator (TPL-25) and a Bluefin-21 Autonomous Underwater Vehicle (AUV), provided by the US Navy.

ping locator
The Towed Pinger Locator (TPL-25)

"Once the equipment have been fitted in, we expect the ADV Ocean Shield to leave for the search area tomorrow afternoon. It will take them about three days to reach the area," he said.''

Once the vessel arrives at the search area, the locating equipment will need time as it searches at a speed of only two nautical miles an hour, and it can scan for a signal at a range of one mile. This means that a more refined search area needs to be determined.

"We need to reduce the search area in order for the equipment to be deployed effectiely. We don't have a defined area yet," said Captain Mark Matthews of the US Navy.

The ADV Ocean Shield will leave the Australian Royal Navy Base HMAS Stirling on Monday afternoon with 11 personnel. It will take them 3 days to get to the search area. That would mean they only have two more days before MH370's black box transmitter battery dies.

ocean shield
The Australian Defence Vessel 'Ocean Shield' at naval base HMAS Stirling on Garden Island, 60kms south of Perth

However, Captain Matthews stated that in his experience, the batteries are known to last slightly longer than 30 days.

"The batteries in the black box transmitter can, at times, last for approximately 45 days," he said.

No Malaysian personnel will be on board ADV Ocean Shield.