Three teams from the USA have arrived in Japan to join in the investigation of the problematic Boeing 787-8 that caused regulators worldwide to ground the aircraft type.
Teams from the US National Transportation Safety Board, the US Federal Aviation Administration and Boeing arrived at Takamatsu airport on 18 January to join the Japan Transport Safety Board's inspection of the aircraft.
The JTSB has removed the affected battery from the aircraft for further checks, says an ANA spokesman.
"We still do not know the specific reason or necessary action for this situation, so we're doing regular maintenance checks on our 787s. Checking on batteries is a part of it," he adds.
The carrier, which is the launch customer of the 787, reiterates that there are no changes to its order of 19 787-8s and 30 787-9s "at this point".
Japan Airlines meanwhile says that checks are ongoing on its seven grounded 787s.
The carrier also revealed that it previously had to replace the batteries on several 787s in its fleet.
This is similar to what ANA said on Thursday, 17 January 2013, that several battery changes had to be made on its 787s before the latest incident on 16 January.
In that incident, pilots observed an error message related to battery malfunction and an "unusual smell" in the cockpit, leading them to make an emergency landing. ANA said the battery in the forward electronic equipment bay was later found to have discoloured and that the electrolysis solution had leaked.