ANA Holdings Inc., the biggest user of Boeing Co. 787s, will send its second battery charger in two months to supplier Thales SA after a message signaled a problem during a maintenance check.

The airline changed the battery during maintenance on Nov. 16 and no flights were canceled or delayed, Ryosei Nomura, a spokesman at ANA, said Monday.

Boeing 787 Dreamliners were grounded worldwide earlier this year after batteries made by GS Yuasa Corp. melted on two planes. The Chicago-based airplane maker made changes to the battery and charger, built by a unit of Meggitt PLC, before flights were cleared to restart.

Japan Airlines Co. earlier this month said it would send a 787 battery charger to Thales after it found no problem with a battery in the plane following a warning light during a Helsinki-to-Narita flight. ANA sent a battery charger for checks in September, after replacing it and finding no problems following a low-battery warning.

U.S. investigators said in January that they found no evidence of flaws in the Securaplane Technologies Inc.-made battery charger after probing it as a possible cause of a fire aboard a Japan Airlines 787 in Boston earlier that month.

Thales supplies the unit that includes the battery and charger to Boeing.

The grounding of the 787 fleet pared ANA's sales by ¥8 billion in the quarter ended in June. JAL, the world's second-largest operator of 787s, said the grounding of its Dreamliners cut sales by ¥4.8 billion in the same period.